The Jones H-bar is an alternative to a flat with ends or the butterfly style. Too expensive but pretty cool--3-4 different positions. Titec is supposed to be coming out with a cheaper, aluminum version sometime soon. North Road bars or Albatross bars are also a nice alternative--I've heard good things about both. I'm happy so far with my Jones (got it used.)
www.jonesbikes.com the H-bar
http://www.bessasandackerman.com/p/0081.php Albatross bar fan club