I remember seeing on Crackberry's main page, about an app for BBs(duh :P ) and it was like a BBM but like a walky talky. they made a big deal about the point that you could call others on a different network, like VZW to ATT.
if anyone could link it, or at least the app name, I would really appreciate it.
I tried a search already, it was a little while ago though