Serratus Crunch?
http://www.T-Nation.com/free_online_article/exercises/exercise_of_the_week_the_serratus_crunch&cr=
[quote]GetTheHIT wrote:
Holding a heavy weight overhead[/quote]
QFT, Get in a rack and put the bar high up on the pins, put a buncha weight on and get in a overhead squat position keep your back tight and try n stand up.