As I suggested here:
Using its ability to decipher language, [OHBot] could be used as a judge... in a SNOHBALL fight. People could sign up for a team, then fling (virtual, posed or emoted) snohballs at each other, and OHBot could be the judge of which team won, who got hit by the most snohballs, who threw the most, etc. Set it up in a snowy Eder Delin and that's entertainment!
Another thought, that I didn't post elsewhere:
In both WoW and Second Life, I've encountered trivia bots. You could probably craft a similar trivia game into OHBot with relative ease. This is a less original idea (copying what I've seen done elsewhere) but it seemed worth mentioning.