Rumors about social networking site Bebo being for sale come up every few months. First it was British Telecom for $550 million in July 2006 (TechCrunch started that one), then the Financial Times reported they were in talks with Viacom a month later. Now, The UK’s Telegraph is reporting that Yahoo is looking, and may pay as much as $1 billion.

Yahoo would have bid as high as $1.6 billion for Facebook last year according to leaked documents. But Bebo, while large and growing, is far smaller than Facebook. And it’s also smaller than Hi5, Orkut, Friendster and Tagged, according to Comscore.

On the plus side, Bebo does claim 25 million users, about a quarter of what MySpace has today. And they are very strong in the UK.