I acutally don't even have texting, but I could think of some good things about it.

-If you want noone else to hear what your saying
-No akward silences, if you just don't reply back once there is nothing to say
-If you just need to send a quick message, like "meet me at the mall at 3" rather than calling them to just say something simple
-Just to say hi, and see how someone's day is going
-You needed to get a phone number or address. You don't need a pen and paper to copy in down, you'll just have it on your phone