When You're Smilin'.... sing it now!

This is by far the best short list to doing something nice. Not to be taken lightly, but always welcome.
The Happiness Project: Five tips for performing easy good deeds.

Surf the Waves

There is nothing more interesting than live science. This comes as close to it as you can be on a PC. No doubt, this is very applicable to a Physics class, but every kid has played with something that displays similar attributes. Enjoy...

stringWave.swf (application/x-shockwave-flash Object)