here are a couple of abs that really surprised me:
get on the linoleum (slippery)kitchen floor with socks on. assume a push-up position, hands approximatey shoulder width apart, maybe wider. put the TOPS of your feet on the floor. (not toes). slide your feet into your torso, bending knees tightly at your chest. tuck in abs to avoid arching your back.
return to starting position. repeat 10 times, working up to 2 sets of 20.
take a 5-pound dumbbell weight in both hands(or as much weight as is comfortable). stand with feet wider than hips, feet pointed out.
bend knees a little deeper than "slightly."
watching form, concentrating on abs, slowly trace a figure-8 in front of you. (the top of the 8, your arms are fully raised above your head, the bottom of the 8 is about at your knees. the center of the 8 is about at your waist.)
gently allow your body to groove with the motion, gently allowing your back to bend as you go. but don't get strainy with it. watch your form. watch your back.
do 2 sets of ten, one set tracing in one direction, the other set, tracing in the other direction.
they're surprising. do the routine just once and see if next day you've got some deep soreness.
let us know, huh?