BrewerJ wrote:+1 on champaign yeast however you need to make a starter for it don't just throw it in. If you brew lagers you can use some lager yeast as they are able to ferment sugars that ale yeast cant. I have used lager yeast to drop the final gravity of a double ipa before.
+1 on the Champaign yeast as well. If it still comes across a little sweet, you want to get it as dry as possible, if you plan on aging it. Remember though, carbonation provides a little bitterness (or dryness if you will) as well, because it helps lift the beer off the palate. Mind you, still beer tastes much different/sweeter (in some instances) than carbonated beer. If you think its close, and you don't want to put any more time and money into it, bottle it, drink a bottle every 2 months or so... and if it starts to get a little too sweet, just drink it all up and brew it again!
BrewerJ, good tip with the lager yeast... I've never heard of that before... Would you pitch it (high krausen of course, with a starter) at ale temps?