Gleb Sabirzyanov reviewedBetterTouchToolFree OS X app to configure custom gestures for your trackpad
 Recommended
Pros: 

Amazingly simple to set up, can't imagine my life without it already! It saves so much time!

Cons: 

Makes life very hard when you don't have it.

I use it from 100 to 700 times per day according to built-in statistics.

Gleb Sabirzyanov has used this product for one year.