Ding! Overleveled to 11
Ding! Overleveled to 11 is an achievement (or trophy) in Borderlands. It is only obtainable via The Secret Armory of General Knoxx DLC Pack. As the name suggests, it involves getting past the former level cap of 50, and reaching the new level cap - 61.
It is a Silver Trophy for PS3, and a 40G achievement for Xbox 360.