Reverse Phone Detective.com / Reverse Phone Look Up Service
Reverse Phone Detective is a TOTAL SCAM. They lure you in by saying you'll have unlimited searches for one year. Then when trying to do a search, they will require you to buy tracer report credits (at $9.95 per credit).
I tested it on my own home phone (a land line) and it told me it was unpublished (it's not), but to find out more, I could buy tracer credits and they'd be happy tell me more.
DON'T WASTE YOUR MONEY!!!