Just finished a nice 2 hour session at the gym, also trying some of the new stuff that was mentioned on the thread.
The mountain climbers on the yoga ball is something though
Its a good excercise for me because the result is very gaining, and theres like hardly any pressure on my lower back.
Its hard to 'not' cheat or slouch and be lazy though.....i guess thats the challenge with all these core excercises.