Xander Soldaat has set up an interesting interface that uses the new Dexter Industries WiFi sensor. The idea is simple: control Xander's NXT from anywhere in the universe that's connected to the internet.
Before I post any spoilers, have a look at his NXT live with this link.
Then, in a different window, send a command to his NXT with the WiFi sensor using this link:
Replace "-99" with any value between -100 and 100 and see what happens.