There's a post over at Marketing Strategy and the Law, "How to Cover a Conference Using Twitter," that give some good advice. Use the "official" conference hash tag, don't bother with quote marks . . . that sort of practical stuff.
I'd like to add my 2¢ worth. (Time to move that expression up-market, don't you think? I mean 2¢ won't even buy penny candy nowadays.) And I should preface it by saying that by and large I'm not a fan of having conferences tweeted at me: I find that the sudden deluge of individually incomprehensible tweets is truly annoying, a wedge of noises inserted into my already static-y flow. In my view this is using Twitter for something that blog posting does better. So:
A. If you're a person who likes to indulge in serial tweeting from time to time, whether of conferences or birthday parties, consider getting a second Twitter account just for that purpose. You can alert your followers that you're about to activate YournameConf again; those who enjoy conference tweeting can head over there; and those of us who like your day-to-day apperçus won't be flooded out because YournameConf isn't someone we follow.
B. If you're not going to do that, at least warn your followers that there's some hail on the horizon so that those who will can take shelter.
How to shelter?
C. Well, you could use Twitter's "block" feature, now that you can "unblock" subsequently.
D. Or, if you're concerned you might hurt someone's feelings with a full block, you might avail yourself of a service like twalala.com, which filters tweets out of your stream in a variety of ways, one of which would be by way of a keyword, such as the conference hash tag. (If only people who feel compelled to pass on pithy quoted advice — "Make sure you're right, then go ahead": Davey Crockett — were required to tag these with a symbol that would let them be muted this way.) Tangerineworks provides Greasemonkey script called TwitBlocker that does pretty much the same thing for folks using Firefox.
E. If you use a desktop or smart phone app to get your tweets, it may offer you a way, short of unsubscribing and resubscribing, to dampen the flow. Tweetdeck's filtering system should be able to help you out here.
*Thank you* for this post, Simon! While some people seem to have a talent for posting minimally useful tweets from conferences, I find that the value-to-noise-ratio is usually tipped to the "noise" end. Your ideas give us strategies to deal with the conference flood.