Yes!  actually 6 sec before, but you can custom your settings. 
eSnipe - Bid on eBay Automatically - eSnipe 3.0
You have to pay for their sevices, BUT only if you win, and it's only 1% of the winning bid price.  You have to buy 500 bidpoints at a time, or more, which is $5.  I think when you first join you get 2 weeks free (if they are still doing that), so bid away for 2 weeks!  Won me a bunch of swag! HAHAHAHA!!! 
ETA: Oh yea, also this way, you can say, Ok i'm only gonna spend *this* much for it, instead of, oh what's a $1 more, and then go over your max.  If the auction goes over your max before the 6 secs, it won't put in your bid and you don't get charged.