You don't have to swing the controller with wii tennis, you can just spin it in your hand. Because you are tilting it on a tighter axis than if you swing, your shots will be as powerful (or more so) than if you swing it as you would playing tennis for real.
I don't have a wii, and have not played wii sports that extensively, but it only took a couple of minutes of experimentation to realise you can "trick" the controller to your advantage by using it in ways other than those intended.
I couldn't do it with wii bowling though. If I didn't find real bowling such a tedious endeavour, I would've been very impressed.
OT: Obviously couldn't harm the wii significantly, but if they had a killer motion-sensing app it could be interesting.







