Charge Enterprises Inc (fka CRGEQ)

[FTWrath]

Not practical at all. Every phone company and every phone manufacturer would have to be on board.
Blackberrys have somethig like this "blackberry messenger" and each user has a unique user name.
Would involve lots of security, and network involvement.
You can't make just any username either because letters correspond to numbers and you would be texting someones actual number.
The idea is okay, however has no chance of being implemented.