There are many well-established beer-related discussion groups yet the real ale one (uk.food+drink.real-ale) has only just been started.
As yet there's a limited amount of real hard-hitting campaigning to be seen, which is a surprise as it's such an effective way to make information available. For instance, journalists are finding the Internet invaluable as a way of researching stories - fast, convenient & efficient.
CAMRA is there, as are many of its branches, with Internet pages and electronic mail. The latter is likely to prove particularly effective when rapid action is required for a campaign - far faster than "snail-mail". The Swindon & North Wilts Branch have a particularly impressive presence, with plenty of campaigning and ads. For instance there's an item about the big-brewery-dominated self-regulatory Portman Group upholding a complaint against Wychwood's Dogs Bollocks beer name. (Incidentally, the group has now set up an independent complaints panel, largely due to the Alcopops fuss.)
The British Real Ale Database by Gary Bleads lists all known beers by brewery, by name and by strength.
BeerScene by Dirk Manuel is the nearest thing to a general monthly campaigning publication. It's an offshoot of the Portsmouth & S.E. Hants Branch Ale Mail and attempts to inform and entertain as to the world of beer. For instance the Business Digest section at the time of writing describes Whitbread's diversification into nursery schools in a big way. There's also a mention of Newcastle Breweries' sponsorship of a mobile police station, complete with logos. There's a particularly good article on the history of the Budweiser brand name.
breWorld is a European collection of information about beer & brewing - very trade-oriented with lots of press releases but still useful. Some of the current items: Interbeer (order beer via the Internet for home delivery), a job ad for a brewmaster in the Caribbean, the new Fenland Brewery in Chatteris and Yixing, the Chinese beer now available in the UK.
The World-Wide Virtual Library: Beer & Brewing section by John Lock aims to catalogue all beer-related resources - home-brewing ones feature prominently in this giant list.
The prize for the most awesome resource however must go to John Adams' Beer Drinking Records - this lists all the beers he's drunk since March 1988, including price and strength. The list is sorted in various ways, such as by beer name and amount drunk.