Instructables is a web site where people post "how-to's" for solving everyday problems and other neat ideas. Most of the articles there are ways to hack items you have around your house to make them into something else. One of the ideas on the front page shows you how to modify a Lego piece into a usb device. Another shows you how to make a rain-harvesting system out of 50 gallon barrels.

It's fun to just browse this site when you're bored or looking for a way to fix a problem.

Instructables.com