Too lazy to dig out your TI graphing calculator? You can run it on your computer, and it’s a lot faster. Get VTI and follow the set up wizard that it comes with to make it possible.
Author: Matt Walsh
TICalc.org has software for any TI graphing calculator, and some software that runs on your computer. Be sure to look thorugh the archives.
Can’t afford Photoshop? The open source GIMP has much of the same functionality and is completely free.
JR Screen Ruler will allow you to measure the size of anything on your screen in pixels. I find it very useful for tweaking web site designs.
20q.net will guess just about any object that you can think of by asking you 20 yes/no questions.