[abayne5]

It's been a long time since I fooled around with a Blackberry. I have a 9780 bold unlocked from T-Mobile and wanted to know how I can convert it over to AT&T. Is there a factory rom that doesn't have the T-Mobile screen or apps? Or do I need to install AT&T books on it?

[BBerryPowerUser]

I used my unlocked 9780 on Att for a while. No issues. The service books should push and update for you. If not you can delete the T-mo books and have Att resend theirs to you. The apps will work, of course. And your App world will access Att once you register the device on the Att network.
The screen does not need to be changed. If the start up T-mo screen really bothers you, ignore it. It's fleeting. Change your wallpaper to an Att theme or logo if you are that loyal to Att.

I went back to T-mo via the prepay MVNO Simple Moble simply because Att was too pricey for me. But Att sure has better coverage.
Simple offers unlimited BIS for a flat $50 a month.

Net net, it will work on Att just fine. Well, at least mine did.