[Update 02-Aug-08: after testing, I'm abandoning this idea. Google calendar is a nice tool, though, and I encourage you to try it if you're organising events, especially if you want to list them on a website, like this.]
So I have been working with the Google calendar beta to see if I can make something useful. Assuming I have updated it, it should show events around the time you're looking at this page. Use the arrows to go forward and back. I started by adding events from the leaflets blu-tacked to my door. So this is not exhaustive, nor do I necessarily endorse the events shown. I just have reason to believe they're going to happen.
If you are an organiser and have your own Google Calendar of milongas or classes in the London area, I think I can add it to this display. I also think it's possible to send invitations to this calendar, which I have set it to accept, but I'm not sure how that works yet.
So far I have added milongas at the Dome, the Crypt (el Once and DanceTango), Vino Latino's, Conway Hall, Negracha, the Adelaide, the Bedford (el Porteñito, which I haven't reviewed yet) and 33 Portland Place. I've also added Tango al Fresco, River Tango, and Ezequiel Paludi and Geraldine [Rojas] Paludi's forthcoming visit to Tango-in-Action.
Caution: Google Calendar has at least one bug that can cause events spanning midnight to be displayed twice, once on each day, as though they were two events. I don't think it does so in the format above, but please comment if you see this.
Please comment too if you have any feedback about whether this looks useful, and what information is most essential to you. You do not need a Google account to comment, just click "Name/URL" and type some name.
My plan is to link to the calendar permanently on the right of this page.