MTB outfitting for TRI??

I have seem many people use a mtn bike for triathon - especially for sprints.  I also think that changing to road tires is the best move you can make.  Should really help with speed.

I'm not sure if getting an aero bar for your mtn bike would help that much.  I'm concerned about what that would do to handling and could cause you problems.  I would suggest not doing that and saving your money.  Road tires and clipless pedals would be your best bet by far....

Just my .02..  Good luck with your sprint!

Lots of people ride mountain bikes (or worse), particularly in sprints. 

Put on slicks, and clipless pedals if you don't already have them.  Aero bars--I wouldn't bother on a mt bike personally, but people do, you wouldn't be the only one.  And if you go with a road bike later on, you can always transfer them.

Slicks are pretty cheap and they will make the ride more enjoyable (i.e fun) but they aren't going to make you any more of a contender for fastest bike split.  If you are looking to win, you need a fast roadie or tri bike, so I can see your point.  Personally, I'd get some cheap slicks, run em at 80psi+ and call it good.  Aerobars are not gonna work that well on the MTB due to the geometry of the MTB.