I was going through some stuff and found a copy of something Fred Hutch wrote on the other board. I liked it so I made a copy. Here is what he wrote:

" Wanted to share my favorite abdominal isos:

1) Low Back Press: Lie on Your back on the floor with legs out straight and a rolled up towel under Your lower back. Now simply press your lower back against the towel, trying to crush it between Your back and the floor. You will have to experiment a little to find the proper thickness for the towel, too small doesn't work so good and too thick strains the back. This iso gives me a harder abdominal contraction than any other exercise I've ever done. It also works perfectly for the Bud Jeffries method of doing an iso and then immediatly doing a movement exercise, since You just have to move Your legs a little and You can do hip lifts and/or situps without moving the towel. In fact the work best with a rolled up towel.

2) Broomstick Twist: Stand close to a wall, hold a broomstick against Your upper chest. Turn and place one end of the stick against the wall and exert force. Work both sides(well duh). Facing the wall is the basic position, but You can also stand with the wall to one side and work both the stretched and fully contracted positions of the broomstick twist. A real favorite of mine, I have long thought twisting exercises are rarely used to their full potential.

3) Wood Chop: I find a kitchen counter is the correct height for this exercise. Stand with the counter to Your side, turn at the waist toward the counter and place both hands on the counter. Now Press down. You should feel the abs and obliques working good. Work both sides. I usually do these with the torso perfectly upright, but You can lean over somewhat and may find this more effective.

Those are my big three abdominal isos. I do them with Steve Justa's four-surge method nowadays, although I have done jerk rep isos too. I have never done them with long holds(1-5 minutes) but sometime I will. I would guess it would give You super-ripped abs in a hurry. Enjoy."