Ugh I wrote a response out and for some reason it didn't post....
What I said, summarizing, was that I get far more calls from BP then all the other sources/boards combined. Allie is right, you have to weed through those calls.
As for screening, you have to do whatever you are comfortable with. A lot of the guys that only know about BP, don't even know what a reference is. I've had some guys offer to give me their siblings, family info to verify them lol. Just let them know you need to know who they have seen in the local area, and be sure that if you are unfamiliar with the lady he gives you, that you check her out to be sure that she is indeed legit.
Good Luck!
Lux