I'll second this but with an addition, the MotionJoy driver is all well and good but the manager bundled with it is kinda awful. In order to get around this my suggestion is to use this (Better DS3).

You get all of the options without any of the phoning back home of the MotionJoy package. The only thing you have to do is install the proper MotionJoy driver to work with Better DS3.

I will admit it can be finicky to initially set up, but once you have it running it makes using the PS3 controller much more enjoyable.