I've been privileged to have cask-conditioned ales twice in the past week, and both attempts have been most successful. The first was Nov. 28 at North by Northwest, which offers a keg of cask-conditioned ale on the last Wednesday of every month. (Now forget I told you that, because I don't want you there — I get very sad when the keg runs out.) The other was Tuesday night at Uncle Billy's Brew & Que. Both were marvelously hoppy pale ales.
If you aren't familiar with the cask-conditioned ale, I'm not sure how to explain it, since I'm not a brewer. I think the way to explain it — and I'm probably wrong — is that after brewing, it continues to mature in the cask, and its carbonation occurs naturally instead of having CO2 artificially pumped in. And to get the beer out, pressure is not pumped into the keg — you either use a pump (common in a lot of English bars) or just use gravity (see the photo). It can taste a bit flat compared to regular bottled or keg beers, but once you get used to it, you realize the flavors can come out much better without all the extra gas. If you've had draft beer in a London pub, you have the idea. A better bet than trusting me is to read this article.
I think it's magnificent. And it's too rare of a treat here in Austin. When I was in Portland, it seemed like every brewpub had a cask-conditioned on tap, and I think I tried every one. You've gotta love the beer snobbery of a city where cask-conditioned ales are expected. (Humulone Red, by the way — he was at both events — disagreed with me. He thought the rarity of it here made it more of a special treat. I also know the Draught House have sometimes featured cask-conditioned homebrews, and the last time I was at the Ginger Man (some time ago), they had a cask version of Saint Arnold's Elissa IPA.
The next time you see a cask-conditioned is being served somewhere, give it a shot. Unless you're in Austin. In that case, I don't want you there taking my beer.