Hi,
Craig, if it is so principial then there is next idea: if an automatic post scaner script has found abbreviation(s) then it:
- either replases SMS with correct words,
- or generates additional lines at the end of original message like:
Note: this message has next SMS(s):
u=you;
cu=see you.
- or make links from SMS to SMS explain list. If somebody does not know what does shortcut mean then he just presses on it and gets description list.

Good days!