Ours moved to $7.25 on July 24, 2009. It had been $6.55 from July 24, 2008 to July 24, 2009, $5.85 from 2007-08, and $5.15 from 1997. Servers (who work for tips) can be paid as low as $2.13 per hour, making the rest up in tips, however, if their tips plus their wage do not equal at least $7.25, the employer must pay the difference.
Anyone from age 16 to age 20 can be paid $4.25 for their first 90 days of employment, but then the minimum must match the minimum wage of $7.25.
To complicate things more, each state also sets their own minimum wage. If it is higher than the federal statutes (listed above), the state's minimum takes precedence. In Texas, where I am, we go to the letter by the federal statutes.
This list gives each of the 50 states' (as well as US territories') minimum wages.