Oh really, I thought the carbonation took longer. I know it is faster then bottling but thought I had read it was a few days at least. Time to do more research.
well, it depends. what denny was referring to is that you can keg, chill and then quick carbonate the keg by shaking or rocking the keg back and forth until no more gas enters the vessel (you can hear it rush in as you shake initially), then let it settle for about an hour and you're good to go.
I'm not much of a fan of doing this since the bubbles are uneven and you inevitably wind up with hazy beer initially - I prefer to gas it slowly over a week or 2 as its conditioning, but I also have 10-15 kegs full at any time, so there's usually no rush.