A friend of mine at a major cellular provider sent me an e-mail showing how this article was sent to employees and used to motivate the salesforce to sell more texting plans.
The PC World article, 10 Killer Texting Tricks, is interesting and some of these are useful. I've used SMS to take notes on the road and jot down ideas for screenplays. I've sent voice packets to friends, but only as experiments. I have yet to try Mapquest (driving directions) or Google using SMS, probably because I see it as a waste of nickels.