Video games and excersize

After reading this article on Dance Dance Revolution being used in some schools for gym class, and reading people's comments I'm thinking:
A. it sounds like a lot of fun
B. it sounds like a good workout for me and the kids
C. if it's as much fun as they're saying, I'd be likely to do it and so would they (and we love to dance, especially silly ones!) This is baby #4 and I'm not as young so I'm sure I'll need as much help as possible getting the weight off.

I'm not a video game person, I was never huge on games in general. I think that's partly my Mom's fault, but I won't get into that one (LOL).......she knows exactly what I mean! I used to play Ms. Pac Man on my grandmother's computer way back when, and I played solitaire and such years later on our family computer but that's about it for computer/video games. It's not something I want to encourage, given all the stories of game violence. If it happens that the kids get into them through friends, than I suppose I will have to investigate to find ones that are ok. I figure my kids get way more violence than they need in their little minds just from some of their father's tv shows! And then there's the whole obesity/sitting in front of the tv or computer thing, blah blah blah, you've heard it all before. Anyway......

So I'm wondering how much it costs; if it's a video game, what type of equipment do you have to have to play it? has anyone heard of or tried it and what did they think?