Best post pregnancy ab exercises?

Suck your gut in while you're at the gym. Seriously, the act of keeping it sucked in will get it toned enough while you do all your exercises. It will also give you upper body support. Dunno if you watch Biggest Loser, but look what that simple act did for "Unc" last season as he triumphantly ascended the stairs to the scale, just because he sucked in his ab muscles and made them support him.

Lay on your back with your legs mostly straight. Dig your heels in, then use your abdominal muscles to pull your legs up. With your heels dug in, your feet shouldn't move. This works really well on a sandy beach.

reverse crunches, leg lifts laying on the floor, double crunches, knee ups sitting on a chair, rocking chairs (lay on the floor with your knees bent and hands under your hips. Bring your knees into your chest like your rocking in a rocking chair then tap the floor when you come down). Also do supermans for your lower back, deadlifts, or good mornings. Your abs and back work as a unit. You can't strengthen one without the other.

My wife has used 10 minute trainer both during and after her pregnancy and has had much success with it. Send me an email if you want any more specifics.