Here are some GeoPDF Topographical Maps (mostly 7.5 minute quads) from the USGS. The maps are probably all in or near California, becuase those are the ones I use.
They are in PDF format - use Acrobat Reader version 7 or higher, optionally with GeoPDF toolbar plugin.
The *_geo.png files are pictures of the maps saved from the GeoPDF files of the same name at high resolution.
PNG is the Portable Network Graphics format (viewable in all modern browsers and picture viewers).

The "GeoPDF" USGS TOPOs available at http://store.usgs.gov/ at the "Map Locator" - these maps give you coordinates and allow measurements!
They are named like <quadname>_OnnnnnLn_geo.PDF, e.g. Mount_Williamson_O36118F3_geo.PDF .
Get the geopdf toolbar for Adobe Acrobat at http://www.terragotech.com/software/GeoPDFToolbar.exe - It's cool - it lets you use coordinates and measure distances, etc. See the developer's home page at http://www.terragotech.com

      Name                                        Last modified      Size  Description
 Parent Directory                                                 -   Parent Directory (Maps)
 Basalt_O38118A3_geo.PDF                     02-Jun-2008 21:11  4.6M  USGS GeoPDF maps
 Beatty_F36116E1_geo.PDF                     25-Apr-2008 19:52  8.9M  USGS GeoPDF maps
 Benton_Hot_Springs_O37118G5_geo.PDF         29-Apr-2008 21:03  8.3M  USGS GeoPDF maps
 Benton_O37118G4_geo.PDF                     29-Apr-2008 21:04  8.1M  USGS GeoPDF maps
 Benton_Range_F37118E1_geo.PDF               01-May-2008 22:37  9.4M  USGS GeoPDF maps
 Big_Pine_O37118B3_geo.PDF                   25-Apr-2008 19:59  7.1M  USGS GeoPDF maps
 Bishop_F37118A1_geo.PDF                     29-Apr-2008 16:19   11M  USGS GeoPDF maps
 Blanco_Mountain_O37118D2_geo.PDF            25-Apr-2008 19:56  9.1M  USGS GeoPDF maps
 Bloody_Mountain_O37118E8_geo.pdf            28-Jul-2008 17:29  7.7M  USGS GeoPDF maps
 Boundary_Peak_O37118G3_geo.PDF              29-Apr-2008 16:24   10M  USGS GeoPDF maps
 Cattle_Mountain_O37119E2_geo.pdf            28-Jul-2008 17:29  7.3M  USGS GeoPDF maps
 Convict_Lake_O37118E7_geo.pdf               28-Jul-2008 17:30  8.2M  USGS GeoPDF maps
 Craig_Canyon_O36117F7_geo.PDF               01-May-2008 22:41  8.9M  USGS GeoPDF maps
 Crooked_Creek_O37118D1_geo.PDF              25-Apr-2008 20:22  9.1M  USGS GeoPDF maps
 Crystal_Crag_O37119E1_geo.pdf               28-Jul-2008 17:30  7.5M  USGS GeoPDF maps
 Darwin_Hills_F36117A1_geo.PDF               01-May-2008 22:42  9.2M  USGS GeoPDF maps
 Death_Valley_C36116A1_geo.PDF               29-Apr-2008 21:48  7.5M  USGS GeoPDF maps
 Death_Valley_Junction_F36116A1_geo.PDF      25-Apr-2008 19:53  9.4M  USGS GeoPDF maps
 Dry_Mountain_O36117H5_geo.PDF               29-Apr-2008 16:42   10M  USGS GeoPDF maps
 East_of_Waucoba_Canyon_O36117H7_geo.PDF     29-Apr-2008 21:48  7.8M  USGS GeoPDF maps
 East_of_Waucoba_Spring_O37117A7_geo.PDF     29-Apr-2008 21:49  7.4M  USGS GeoPDF maps
 Excelsior_Mountains_F38118A1_geo.PDF        02-Jun-2008 21:09  8.4M  USGS GeoPDF maps
 Fish_Springs_O37118A3_geo.PDF               25-Apr-2008 19:55  6.7M  USGS GeoPDF maps
 Flagstaff_C35110A1_geo.pdf                  30-Sep-2008 16:25  5.1M  USGS GeoPDF maps
 Flagstaff_F35111A1_geo.pdf                  30-Sep-2008 16:25  7.2M  USGS GeoPDF maps
 Fresno_C36118A1_geo.PDF                     25-Apr-2008 19:55  9.1M  USGS GeoPDF maps
 Goldfield_C37116A1_geo.PDF                  29-Apr-2008 21:50  7.0M  USGS GeoPDF maps
 Graveyard_Peak_O37118D8_geo.pdf             28-Jul-2008 17:53  8.4M  USGS GeoPDF maps
 Hammil_Valley_O37118F4_geo.PDF              29-Apr-2008 21:51  6.5M  USGS GeoPDF maps
 Humphreys_Peak_O35111C6_geo.pdf             30-Sep-2008 16:25  3.9M  USGS GeoPDF maps
 Huntoon_Spring_O38118A5_geo.PDF             02-Jun-2008 21:11  5.7M  USGS GeoPDF maps
 Huntoon_Valley_O38118B5_geo.PDF             02-Jun-2008 21:10  4.1M  USGS GeoPDF maps
 June_Lake_O37119G1_geo.pdf                  28-Jul-2008 17:31  7.8M  USGS GeoPDF maps
 Juniper_Mountain_O37118F2_geo.PDF           25-Apr-2008 21:40   10M  USGS GeoPDF maps
 Kearsarge_Peak_O36118G3_geo.PDF             01-May-2008 22:39  8.5M  USGS GeoPDF maps
 Koip_Peak_O37119G2_geo.pdf                  28-Jul-2008 17:31  9.3M  USGS GeoPDF maps
 Last_Chance_Range_F37117A1_geo.PDF          01-May-2008 22:38  8.7M  USGS GeoPDF maps
 Last_Chance_Range_SE_O37117A5_geo.PDF       29-Apr-2008 21:53  9.4M  USGS GeoPDF maps
 Last_Chance_Range_SW_O37117A6_geo.PDF       29-Apr-2008 21:54  9.1M  USGS GeoPDF maps
 Little_Huntoon_Valley_O38118B4_geo.PDF      02-Jun-2008 21:10  3.9M  USGS GeoPDF maps
 Lower_Warm_Springs_O36117G7_geo.PDF         29-Apr-2008 21:55  6.7M  USGS GeoPDF maps
 Mammoth_Mountain_O37119F1_geo.pdf           28-Jul-2008 17:31  6.3M  USGS GeoPDF maps
 Manzanar_O36118F2_geo.PDF                   20-Apr-2008 12:11  5.8M  USGS GeoPDF maps
 Marion_Peak_O36118H5_geo.PDF                25-Apr-2008 19:33   10M  USGS GeoPDF maps
 Mariposa_C37118A1_geo.PDF                   01-May-2008 22:41  8.9M  USGS GeoPDF maps
 Mount_Abbot_O37118D7_geo.pdf                28-Jul-2008 17:53  9.4M  USGS GeoPDF maps
 Mount_Barcroft_O37118E2_geo.PDF             25-Apr-2008 20:23  9.5M  USGS GeoPDF maps
 Mount_Brewer_O36118F4_geo.PDF               24-Apr-2008 21:02  9.0M  USGS GeoPDF maps
 Mount_Clarence_King_O36118G4_geo.PDF        20-Apr-2008 12:32  9.6M  USGS GeoPDF maps
 Mount_Dana_O37119H2_geo.pdf                 28-Jul-2008 17:32  8.8M  USGS GeoPDF maps
 Mount_Darwin_O37118B6_geo.PDF               29-Apr-2008 15:15   11M  USGS GeoPDF maps
 Mount_Goddard_O37118A6_geo.PDF              25-Apr-2008 20:10   11M  USGS GeoPDF maps
 Mount_Langley_O36118E2_geo.PDF              20-Apr-2008 12:40  8.4M  USGS GeoPDF maps
 Mount_Lyell_O37119F3_geo.pdf                28-Jul-2008 17:32  7.5M  USGS GeoPDF maps
 Mount_Montgomery_O37118H3_geo.PDF           30-Apr-2008 12:12  8.7M  USGS GeoPDF maps
 Mount_Morgan_O37118D6_geo.pdf               28-Jul-2008 17:54   10M  USGS GeoPDF maps
 Mount_Pinchot_O36118H4_geo.PDF              20-Apr-2008 12:32  8.5M  USGS GeoPDF maps
 Mount_Ritter_O37119F2_geo.pdf               28-Jul-2008 17:32  8.2M  USGS GeoPDF maps
 Mount_Thompson_O37118B5_geo.PDF             25-Apr-2008 19:54  9.7M  USGS GeoPDF maps
 Mount_Whitney_F36118E1_geo.PDF              24-Apr-2008 21:15   12M  USGS GeoPDF maps
 Mount_Whitney_O36118E3_geo.PDF              20-Apr-2008 12:40  8.1M  USGS GeoPDF maps
 Mount_Williamson_O36118F3_geo.PDF           20-Apr-2008 12:10  9.6M  USGS GeoPDF maps
 New_York_Butte_O36117F8_geo.PDF             25-Apr-2008 19:59   11M  USGS GeoPDF maps
 North_Palisade_O37118A5_geo.PDF             25-Apr-2008 19:38   11M  USGS GeoPDF maps
 Old_Mammoth_O37118F8_geo.pdf                28-Jul-2008 17:33  7.8M  USGS GeoPDF maps
 Pat_Keyes_Canyon_O36117G8_geo.pdf           29-Apr-2008 20:58  9.4M  USGS GeoPDF maps
 River_Spring_O37118H5_geo.PDF               02-Jun-2008 21:12  5.4M  USGS GeoPDF maps
 Saline_Peak_O36117H6_geo.PDF                30-Apr-2008 12:21  9.6M  USGS GeoPDF maps
 Saline_Valley_F36117E1_geo.PDF              01-May-2008 22:39  8.8M  USGS GeoPDF maps
 Sand_Flat_O36117F4_geo.PDF                  29-Apr-2008 17:11  9.7M  USGS GeoPDF maps
 Sharktooth_Peak_O37119D1_geo.pdf            28-Jul-2008 17:52  8.1M  USGS GeoPDF maps
 Shaver_Lake_F37119A1_geo.pdf                28-Jul-2008 17:52   10M  USGS GeoPDF maps
 Split_Mountain_O37118A4_geo.PDF             01-May-2008 22:40  8.6M  USGS GeoPDF maps
 Station_Peak_O37118E1_geo.PDF               30-Apr-2008 13:08  7.9M  USGS GeoPDF maps
 Teakettle_Junction_O36117G5_geo.PDF         25-Apr-2008 19:47  7.8M  USGS GeoPDF maps
 Three_Rivers_F36118A1_geo.pdf               25-Apr-2008 19:32   12M  USGS GeoPDF maps
 Tin_Mountain_O36117H4_geo.PDF               30-Apr-2008 13:15  9.7M  USGS GeoPDF maps
 Tioga_Pass_O37119H3_geo.pdf                 28-Jul-2008 17:33  8.1M  USGS GeoPDF maps
 Toms_Place_O37118E6_geo.pdf                 28-Jul-2008 17:34  7.5M  USGS GeoPDF maps
 Truman_Meadows_O37118H4_geo.PDF             02-Jun-2008 21:13  5.6M  USGS GeoPDF maps
 Truman_Meadows_O37118H4_geo.png             30-Apr-2008 13:24   30M  USGS GeoPDF maps converted to high resolution picture
 Ubehebe_Crater_O37117A4_geo.PDF             30-Apr-2008 13:26  7.0M  USGS GeoPDF maps
 Ubehebe_Peak_O36117F5_geo.PDF               30-Apr-2008 13:33  9.3M  USGS GeoPDF maps
 Walker_Lake_C38118A1_geo.PDF                02-Jun-2008 21:10  7.4M  USGS GeoPDF maps
 Waucoba_Canyon_O36117H8_geo.PDF             30-Apr-2008 13:35  8.8M  USGS GeoPDF maps
 Waucoba_Mountain_O37118A1_geo.PDF           29-Apr-2008 21:01  9.4M  USGS GeoPDF maps
 Waucoba_Spring_O37117A8_geo.PDF             30-Apr-2008 14:13  9.1M  USGS GeoPDF maps
 West_of_Huntoon_Spring_O38118A6_geo.PDF     02-Jun-2008 21:11  5.9M  USGS GeoPDF maps
 West_of_Teakettle_Junction_O36117G6_geo.PDF 30-Apr-2008 14:15  9.2M  USGS GeoPDF maps
 West_of_Ubehebe_Peak_O36117F6_geo.PDF       25-Apr-2008 19:50  5.6M  USGS GeoPDF maps
 Westgard_Pass_O37118C2_geo.PDF              25-Apr-2008 19:47  9.6M  USGS GeoPDF maps
 White_Top_Mountain_O36117G4_geo.PDF         25-Apr-2008 19:47  9.9M  USGS GeoPDF maps
 Yosemite_Valley_F37119E1_geo.pdf            28-Jul-2008 17:34   11M  USGS GeoPDF maps