Hubski has an affectionate tradition of giving people shorter nicknames (not dissimilar from the Russian tradition of dimunitive names, which is adorable). Not everyone is blessed with one-syllable names on Hubski. The list, for such a small community, is extensive:
kleinbl00 is kb
thenewgreen is TNG
_refugee_ is ref
OftenBen is OB
blackbootz is bootz
insomniasexx is insom
johnnyFive is j5 (though I admit: I might have been the only one using it so far)
and there's me as TFG
(those are the ones I know and remember; don't mean to exclude anyone)
So, my idea is to allow registering "mention" nicknames. Those are the nicknames that, when used with the @@ sort of a mention, link to the appropriate user (for example, @TFG@ would link to /user/ThatFanficGuy). This is to aide information propagation through mentions that are quicker to type.
Each user chooses their mention (a single short nickname - that should be enough for everyone), which they set in their settings. Mention-nicknames should be allowed to change, though I don't see who would change theirs once a short name is stuck. For example, someone once called me FFguy over IRC, but I've always been TFG for everyone around.