There are many places on the internet to find databases of sex offenders. The Investigative Programs Crimes Against Children unit of the FBI provides updated links to the sex offender registries of all 50 states. See the State Sex Offender Registry Web Sites by visiting http://www.fbi.gov/hq/cid/cac/states.htm.
Another new website, The National Sex Offender Public Registry, coordinated by the Department of Justice, is a cooperative effort between the state agencies hosting public sexual offender registries and the federal government. The site does not yet contain information for all 50 states. This web site is a search tool allowing a user to submit a single national query to obtain information about sex offenders through a number of search options: