Search on Newegg.com. That's probably your best bet...
EDIT: I figured since I work at Intel at the NWPD station and we do the microprocessor products, I have seen Pentium 4's come through at 3.6GHz, but I believe they were LGA775. But I'd still check Newegg.com though, because I don't pay to much attention to socket or any of that, we package them to fast to notice what kind of processor we're packaging in the first place! But in training we used S478 P4's.
So that should as well, tell you something.