We don't know what model or brand of aero bars you have. I've got Syntace C2's and they came with a computer/light mount. If you can't do that then you could use the thing from Profile Designs. I think that would work good. Or get a bar extender.
If you feel ambitious you could make one of these.
http://www.thaimtb.com/forum/viewtop...5735&start=345