aau007 -- thank you for the very detailed description!

I've finally gotten my PPC to work as a modem for my laptop via bluetooth. It turns out that I was 99% of the way there when I made my last post. The catch, sadly, had nothing to do with missing a step (as posted by aau007). It turns out that (for reasons I cannot imagine) some of us need to enter something in the username/password fields in windows dial up networking, and some of us don't.

All I had to do is enter my phone number (just digits -- no dashes, spaces, etc) into the username field and my regular sprint password into the password field. That's all it took. I never thought of trying that because everyone kept saying "keep the fields blank." But apparently, some of us can't do that.