Who is the oldest football player but still playing football?

For the 2011 NFL season, the following players were the oldest in the NFL:

John Kasay, 2011 New Orleans Saints (42) Position: Placekicker

Jason Hanson, 2011 Detroit Lions (41) Position: Placekicker

Mark Brunell, 2011 New York Jets (41) Position: Quarterback

Jon Kitna, 2011 Dallas Cowboys (39) Position: Quarterback

Adam Vinatieri, 2011 Indianapolis Colts (38) Position: Placekicker

Kerry Collins, 2011 Indianapolis Colts (38) Position: QB

Olindo Mare, 2011 Carolina Panthers (38) Position: Placekicker

Casey Wiegmann, 2011 Kansas City Chiefs (38) Position: Center

Brian Dawkins, 2011 Denver Broncos (38) Position: Safety