A Good, Free Registry Cleaner..?

Unusual for me, a software recommendation:

CCleaner - a tidy registry cleaner and file deleter, free at full-strength and appearing to work well (my Compu-brain 9000 runs a little faster easier), running Vista at least. It feels like you just flossed after about a year.

Half of this is optimistic projection I assume, but it still seems unusually good.