Yeah I bought one because I can't really do situps without hurting my back. I did it for 3 minutes without stopping and got a good burn. If it gets too easy in the future maybe I can get one like your dad's that lets you add weights.

By the way if you wanted to know what it looks like this is it:



http://www.fitnessquest.com/ablounge/Ab_Lounge.htm

They say $164 but I got mine for $75