A new version of BoxWrap2d (http://www.jbox2d.org/processing/ - it's a wrapping of the JBox2d physics library, which I also maintain, for Processing) should be online soon with several bugfixes and added features, along with some tutorials, but in the meantime, I put together a quick demo using BoxWrap2d, the SMS library, and OpenGL to give an idea the kinds of things that you can do with very little effort using these libraries.

The link: http://www.jbox2d.org/processing/SMSBoxWrap2d.zip

It's done as an application since I don't know how to get the SMS stuff working in an applet, so sorry, you've got to download it.

Click to spray circles, and tilt your laptop for literally dozens of seconds of physics fun before you get bored and go do something else!  Press any key to reset the simulation (if you fill it up with circles, for instance).  Pretty basic, I know, but for only ~120 lines of code, there's a lot going on.

Unfortunately to use this you'll need a sudden motion sensor thingy on your laptop, which probably means you need a Macbook of some sort (do any other laptops have this yet?  Maybe I'm wrong and they do...).  Eventually I plan to put together a Wii enabled demo as well, which could also be cool.

Wiimotes are, indeed, Bluetooth.  DarwiinRemote (http://sourceforge.net/projects/darwiin-remote/) allows interfacing of Wiimotes through Bluetooth, you might also check out DarwiinOSC (http://code.google.com/p/darwiinosc/).  Both of these only seem to be for OS X; I know there are lots of Windows ones out there but I haven't actually tried any of them.

Right now my brother has my Wii (he took it with him to college...grrr!) so I can't play with this, but eventually I'll either go take it back or just buy another Wiimote.  Hopefully I'll have something to show soon...