just cut it until its comfy =]

edit: for the sake of saying something productive, i run mine a little narrower than i should, but when i step on my brother's dj or dh bike i find that i actually have less control with its wide ol' bars.

it really depends what you're doing on the bike i guess,
if you're just looking cool, cut it until it looks like those thomson joke bars [pic please]
it you're wikid freestylin', make sure it clears for barspins
if you're on the track, make your drops slightly narrower than your shoulders
and if you're a pervert just get the ***** bars and be done with it =]