This initiative was started with this tweet by Jeremy Cliffe. Then things started to get going rather fast, with people emailing Jeremy and retweeting his original tweets, and it was clear he had hit upon something. If you want to speak to Jeremy about the initiative then please see the press page. The summary of some of what Radicals UK would work for can be found in this thread.
Jon Worth registered the Twitter name (@RadicalsUK) and the domain name for the website, and got the WordPress site running. The site is hosted by EZPZ Hosting in the UK. You can download the forest image here, and the R logo here. The standard Radicals UK green colour is #6f9331, the yellow R #fffac6, the font is Ubuntu for headings and Open Sans for body text.
More information will be added here as soon as it is available!