Vision 20/20 offers a free web based mashup of sex offender data and Windows Live Maps.

Users simply add their address, city and/ or zip code to the Vision 20/20 site, and then the locations of sex offenders in the immediate vicinity are displayed over a map. Clicking on each sex offender leads to a profile which includes the name, address, and crimes of the sex offender, as well as a mug shot.

It does seem like a rather logical use for a maps mashup, and it functions well. According to Vision 20/20′s publicity there is 650,000 registered sex offenders in the United States, now everyone can find out where they live.