There are a few, but no way to sort by BC, or have it displayed initially without clicking down into each individual bullet. That would be pretty useless.
There is this though:
http://www.shootforum.com/forum/bulletdb.html
Not entirely sure how often it is updated however... Missing Hornady 225's in .308 caliber - those have been around for a little bit now.
Some individual manufacturer's sites have "add to comparison" options too. Hard to go wrong with whatever Berger is offering, mostly.