Skull crushers

lay flat on a bench with the barbell (probably an ezcurl bar) held above you (as in the top position of a bench press.) keeping your elbows fixed, allow the bar to come down towards your head.

http://www.bodybuilding.com/fun/exercises.php?Name=Lying+Triceps+Press

Do them correctly and they can really kick your butt too!!!  The other day I did them on My Tri day and when I went to put my seat belt on in my car I couldent reach lol I had to move my body up more. 

Hey Skull crushers and close grip bench presses are the 2 best exercises for adding tricep mass and strength.

"OOOH"! "I get it!" It uses gravity and isolation of the tricep. Thanks! Can't wait to try it out!!

as a side note.. start with low weight when first trying these.. or you will crush your skull :D... or make sure you have a good spotter....

an alternate way to do these is on an incline bench..

Warm up good or your elbows will start hurting b4 your tricepts.

The key to this exercise is good form; make sure you keep your elbows in and not bowed out.  Also, for an "extra" workout, put the bar above your chest after your last rep and do some close-grip bench presses.  But be careful, since the triceps will fail pretty fast.....

Or on a decline bench that will really change the angle and make you cry.