Android: Text messaging abbreviations are useful for the message sender, but annoying for the recipient. SMS Corrector converts incoming text talk (or txt tlk) into good English or French to save your sanity.
The free app might not catch all misspellings (e.g. it didn't translate "u" into "you"), but it does do a good job with most commonly used text message shorthand, like "b4" and "msg". (Note: in the screenshot above, the text message was sent to my mobile via Gmail, which added weird characters that SMS Corrector translated into other weird characters; this doesn't happen in normal phone-to-phone text messaging.)
SMS Corrector lets you choose whether you want to have the correction appended to the original message, sent as a new message, or replace the original message completely. You can also have corrected words shown in uppercase so you can see what was edited.
If bad SMS spelling is a pet peeve of yours, head on over to Android Market to get clearer incoming messages.