Here is the website of the Liberal Party's catchily-named campaign against the euro. Looks like this one has been won, at least for the time being, but the website remains up. It includes downloadable posters and car stickers. Who knows, it could become a useful resource again if Labour ever revive their efforts to join the Single Currency.
http://www.stufftheeuro.org
(Appius - to reserve this thread for Liberal Party links, I've taken your interesting post about the euro and split it off as the start of a separate thread in the Policies area. Hope that's okay.)