http://www.rangevoting.org/GerryExamples.html A paper on a nifty algorithm for drawing up representative districts fairly.

http://www.mapmsg.com/games/statetris/usa/ Tetris done with the states as pieces.

http://www.veoh.com/browse/videos/category/music/watch/v379444BDX7HcEw Gay Pimp - Soccer Practice

http://www.chorewars.com/ Chore Wars is an RPG based around completing household chores.

http://www.moanmyip.com/ Hear a sexy voice read out your IP address.

http://users.softlab.ece.ntua.gr/~ttsiod/buildWikipediaOffline.html This guy wrote a nifty program to index, search and display a local copy of Wikipedia.

http://lpcoverlover.com/2010/07/18/no-spitting/ Cultural gap.

http://www.precision-gps.org/ Open source software that uses multiple GPS receivers to find the distances between them.

http://pubs.er.usgs.gov/usgspubs/pp/pp1395 A paper reviewing the different map projections used by the USGS.

http://www.walkscore.com/ Measure how walking accessible your neighborhood is!