If you're talking about the carrier line (has the BT symbol on the right side), you'll most likely have to do a regedit.
There are also several applications out there that utilize the carrier line and replace it's text with relevant data. I use TreoAlert and have that line show signal strength, battery status, and memory when it's not showing missed calls or messages.
http://discussion.treocentral.com/sh...d.php?t=144509