I've got the Motorola Droid from Google through their device seeding program a while ago. Which is nice although Nexus One would be much better since then I would have been actually using as my phone. The Droid has to be tied to Verizon and I am a T-Mobile lad all the way.
Anyways, I've tried a few times to get adb debugging talk to my Droid on my Win7 64 bit and I could not get it to work for a long long time. I tried to search around for the solution, but none of the drivers that I've found worked until today I started the search again and found the Win7 64 bit Droid drivers from Motorola here which worked perfectly fine!
Don't forget to go to "Settings->Applications->Development" and enable "USB Debugging"