What to do with weak one card strt/flush draws

[aargh57]

A hand I was just playing made me post this question as it comes up pretty frequently. (6 max)
I had 3 [img]/images/graemlins/club.gif[/img]6 [img]/images/graemlins/heart.gif[/img] in the BB with 4 players total.
Flop came 5 9 J all [img]/images/graemlins/club.gif[/img]'s.
UTG (very LP) bets and gets 2 callers. I have 7 to 1 to call but I've only got the little 3 [img]/images/graemlins/club.gif[/img]. I called only to drop when a blank hit and it was raised when it got back to me.
What value do you put on one card strt/flush draws when drawing? Especially weak ones like this? Would I have been better off just to drop it on the flop?