Make a gift box from two bills (as in money)

For a tiny gift, like a ring or a light necklace.

http://members.cox.net/crandall11/money/box/ 

For students of music: Metronome Online

An easy to use, free online metronome to use while practicing. Also generates an A440 for tuning.

http://www.metronomeonline.com/

100 ways to save the environment

http://www.seql.org/100ways.cfm

Interesting High Speed (super slo-mo) videos

http://www.engr.colostate.edu/~dga/high_speed_video/