To my knowledge, the answer is always no.
To fully experience the flavor of beer, one must swallow it. This is because, unlike the vast majority of wine, beer is carbonated (albeit to varying degrees). When you swallow beer, some of the carbonation escapes the liquid as gas, and actually rises up from your throat into your nose (or, at least, into your nasal passages), carrying with it some of the flavor molecules of the beer. Thus your sense of smell combines with your sense of taste to produce an overall sense of flavor in a manner that is different from what occurs when you drink (uncarbonated) wine.
If you spit out your beer, you're ruining the experience.
(This explanation is based on one that I heard years ago from a brewmaster at Anheuser-Busch. I can't remember his exact words, but you get the gist.)
On a side note, regarding the important relationship between taste and smell, I'm sure you will see tasters at both beer tastings and especially wine tastings swirl their drink a bit to smell it from the glass before tasting it. The difference is that carbonated beverages pack a smell double-whammy coming at you after you swallow.