900#'s and Other Pay Per Use Services Using Your Telephone
What Are Pay-Per-Call and Information Services?
900 numbers are pay-per-call services and generally involve a fee based on usuage(per minute) or a flat fee. These can be quite large depending on the service that you are using. The FCC receives a large number of complaints about 900 numbers each year.
If you get your bill and see information service charges or 900 number charges you can dispute these if you feel you don't owe them..
More information on this can be found at: www.fcc.gov