I have had zero network since between 1 and 4 today with T-Mobile - anyone know what's going on?

Weird...I've got T-Mo and had 5 bars as always all day. Maybe something's up with your phone?

You see, I'd call Kevin to find out (his folks provide my service and he's at their place), but the landline doesn't cover long distance; I can only call him on my cell...

I have no idea how to do it on any phone but my own, so unless you also have a BlackBerry Pearl I can't provide exact directions, but go through your settings and somewhere should be an option like network selection. Make sure your phone didn't somehow get set to use Cingular's network.

Since T-Mobile and Cingular are both GSM, their phones can connect on each others network, but since they don't have roaming agreements in Rolla, the phones won't be able to do anything except make a 911 call.

Registered with T-Mobile...

That did it, 3 bars, thanks!

Good. Although it's kinda weird how your phone got set to use a different network....

The only thing that happened today was that I worked at a place where inside you can't get reception from noon to five today, but it's never switched networks before.

Ya got me.

That has happened to me before. I was in a phone interview and it lost service for about 3 hours. I called T-Mobile using another person's phone and they said that it rarely happens that the network your phone is used to shuts down and for some reason your phone won't search for another network. I shut down my phone and the T-Mobile guy reset my network preference through his computer, and I haven't had any trouble since.