Although my iPhone (
) makes BST'ing on the move SO much easier, I've also wondered what it would take to implement something like this, as Facebook does.
Certainly, it would not be simple, and I would not expect it any time soon... But to receive a PM as a text message, and to be able to reply as such... Would be awesome. I'm not sure how feasible the "replying" would be, but I know the former couldn't be TOO difficult.