For the Busygal Bride

I can speak from first-hand experience as a bride: White House Black Market has some fantastic options for bridesmaids dresses. Obviously, your color options are a bit limited, but if you're in the market for black dresses (and lately they've had some blues and reds sneak in there, too), you're in luck!
Another fantastic option: JCrew. Every friend I have that has worn a JCrew bridesmaid dress has raved about her dress and has exclaimed that she can actually wear it again (every bride's dream come true!). I know for a fact that WHBM dresses will also be worn again...my bridesmaids did!
Both WHBM and JCrew also offer wedding gowns.