Whilst perusing my favorite deal site a few months back (don't worry, they won't all begin this way...) I ran across a discount coupon for Sharper Image. Generally, we stay away from this place like the plague... it's filled with overpriced things that you really don't need. However, in this case, they had something we'd been shopping for for several months. (No Jason, even after the coupon, it wasn't as cheap as your deal!)
The Roomba Discovery is a one-trick robot. It vacuums. End of story.
The good news is that it does it very well, and without too much human intervention. You let it loose, and it starts going in circles until it finds the edge of the room, runs its way around all the walls, and then wanders all over the floor until it decides that it's sucked up all that it can, and then it goes home to recharge itself. Other folks have told us that it does a really good job terrorizing animals, but we haven't been able to test that feature. Whenever our friends' kids come over, they get a kick out of it too.
On the one (rock) to ten (Tivo) scale, Roomba gets about an eight. It needs about one more generation of AI to keep it from getting tangled up in cords and to navigate oddly shaped rooms (like most of ours.) Plus, despite trying alkalines and investing in some monster rechargeables, we're having issues with our Roomba seeing its virtual walls. I've called iRobot and left a message... updates as they're available.