Kara talked me into playing Mario Kart over Nintendo Wi-Fi. We suck. We tied twice. But she sucks more because she plays more than I do so she should be able to beat me every time.
Speaking of online gaming... they added Uno to Xbox Live recently. I played the single player demo. I don't imagine it would be all that much fun unless you play people you know. I'm surprised they haven't done some kind of Texas Hold 'Em on there. That would be fun with the voice chat and such.