Hi, not sure if you can find something like this anymore but i have some old profile aero-bars i got off clearance in a nashbar magazine for 20 bucks, probably 8 years ago.
It's not the best picture of the bars but it's basicly an extension to bar ends, where they meet in the middle.
I went to a mountain bike for getting around town (college town in michigan) after i crashed my road bike and wanted something a bit more stable for curbs and sidewalks.
My bike is actually getting older so i'm starting to weigh stuff to get a new bike right now but i'm very much considering taking the aerobar off my old bike and put on whatever new mountain bike i get.