Through a series of events, I've found my Droid is actually on the Alltel network, though the plan is a recent plan, created directly with Verizon..
You can check via Settings, About Phone, Status, PRL Version
If you're 65XXX, you're on Alltel
If you're 51XXX, you're on Verizon
I guess that massive amount of Pandora streaming I did the first couple of months got me pushed to the Alltel network, since I know I was on the Verizon network initially..
I'm just wondering what everyone else is on..