I'm fascinated by how the Wii Remote Controller (barely visible on the right) makes you think it's doing more than it does. You put this "sensor bar" on top of your TV, and you think that it's somehow magically detecting exactly where in 3-dimentional space your "Wiimote" is. I mean, you can move it, and it detects that, and you can even point at things on the screen. But in fact, the Wiimote is actually two completely separate technologies.
(1) There are accelerometers inside the controller that detect orientation and, well, acceleration. What it does NOT do is detect POSITION in any way, but it gives the illusion of detecting that through human behavior. For instance, in the boxing game, you kind of naturally hold your controllers up vertically to keep your fists high, and you kind of naturally hold them horizontally when your arms are down low.. But the game doesn't actually know if your arms are high or low. You can test this by turning your hands while holding them high: The game starts thinking your fists are low, etc. So how can you point at things on the screen if it doesn't know the position of your controller?
(2) The "sensor bar" atop your TV is not sensing anything at all. Instead, it's actually just a couple of IR lights. it's your Wiimote that actually has a camera! There is a calibration screen where you can see this in action, and that's what's pictured here. What you see is the view from the Wiimote. It sees the two dots of the "sensor bar" near the bottom right, tilted right, so it knows that you're actually pointing the controller at the top left, and tilting it left. Awesome, no? In fact, there's a YouTube video of a couple of guys using two regular remote controls to simulate the sensor bar.
The sensor bar in this picture is the thing with purple dots on top of the TV. Here's a close-up:
What's neat about this is that those lights are completely invisible to the naked eye, because they're infrared, but the CCDs on my digital camera pick it up somehow. Just another reminder that cameras and eyes actually work differently. :)
P.S.: I brought my Wii to Thanksgiving dinner. Even though I only have one controller, it was still a hit among the "adults". My mom got really into the bowling game. If Nintendo can keep releasing games that are as accessible as Wii Sports, they could really expand their market. I think the tough part now is getting the third parties to think in that mindset.