You are forgetting one thing...this doesnt work as msn does...When you make the

emo in msn, the ddp gets all smiley and bla bla...
Now in forums, when you post and put the

emo, it would change ur avatar in every place u had posted before, so where u posted

would become

...got it?
Solution :
User A posts

in thread AA...So, in that post, in thread AA,his avatar remains
Forever...1 minute later the same user A posts in thread AB, with the

emo...so like in thread AA his avtar will be

forever...
Now i dont think that'd be a good idea..phearps a field, bellow your Post count, Reputation, Age, Sex, Joining date and status, saying, POST MOOD =

,

,

or anything