Ok...PLEASE, PLEASE do not fall for this! I have yet to see anyone be able to "spot" reduce! I'm afraid you will need to diet and exercise! You can do crunches all day and not lose any fat unless you expend MORE than you take IN. It truly is as simple as that. Doesn't sound glamorous or sexy but true.
The ab lounger is probably effective and will give you a good workout, but its totally unnecessary. There are a million ways to work your abs without any expensive equipment.
But Terry is right, you cannot spot reduce. Good abs are result of low body fat, and not so much which exercises you pick.