Might be interesting...although in such cases I'm reminded of a quote I saw once.
"Software engineering is a race between programmers, who strive to produce fool-proof software, and the universe, which strives to produce bigger fools."
(Underneath: "So far, the universe is winning.")
That really is a good idea, but I think it would definitely stop a lot of people from using online forums.
I think that although some people are commonly known for typing "lolllolllll!!!!1111" kind of messages, some of them (when the message is decoded back to English from the SMS language of today) are actually useful posts.