Kara Swisher broke news that Facebook and Twitter have ended several weeks of “serious talks,” in which Facebook was offering to acquire Twitter for $500 million of its stock. It appears the talks broke down because Twitter executives and Facebook couldn’t agree about actual worth of Facebook stock.

TechCrunch also reported that at the recent Web 2.0 Summit, moderator John Battelle asked Facebook’s CEO Mark Zuckerberg on stage if Facebook would be interested in buying Twitter. Zuckerberg’s response was: “we’re really impressed by what they’ve done”, and that they have “a very elegant model”.