Toggling Squares is not that Trivial...
Well, this page is not ready yet, and will take some time to be written.
For the time being, the Java game, I'm referring to can be found here: http://www.ida.net/users/housley/atag.htm
I have also written an implementation of it in JavaScript. It can be found here:
http://www.iglu.org.il/shlomif/toggle_squares/
You should experience with it, and try to figure out a methodical way to solve it. Afterwards, you can read this report which I prepared for Ken Housley, who programmed the game applet. The report describes an algorithm which we figured out to solve the game, and proves why this algorithm is working.
I frequently used many Linear Algebra terms there, so you may need to be familiar with this field to fully understand it. When I prepare this page, I will try to explain everything with more basic material, but for now, this will have to do.
