Click pictures for rotatable viewer

Map Info

Mapblast

Basic street map

SF Muni

Transit map (beautiful full map of SF!)

Topozone

Online web app that lets you access scanned USGS topo maps

dlgv32 with data from BARD.

GIS data and viewer supplied by the USGS. Free, fun stuff. The BARD data is slightly corrupted, I wrote a quick perl script to fix it.

Terraserver

Great browser for satellite photos.

Globexplorer

Colour satellite photos!

The Gimp

Excellent image editing software.