Rumor of the day in techville is that Google is interested in buying Twitter, a story floated by Michael Arrington.

It would be a return trip to the First National Bank of Mountain View for the Twitter founders, who previously sold Blogger to Google.

But Arrington tamped down the froth with updates to his post, suggesting it could be just a search partnership and then referring to a blog post by Twitter co-founder Biz Stone that it shouldn't be a surprise that the hot startup regularly talks to various companies.

Could Arrington's story be the product of hopeful brokers? Maybe they're amping up the Google talks to get the price higher and motivate other potential buyers.

It's a smart time for Twitter to sell: The microblogging service seems to have hit the peak of its buzz. It's becoming mainstream, and the corporate marketers embracing Twitter as the latest social media tool haven't tarnished its techie hipster image too much yet. (About the same point at which Google bought Blogger in 2003?)

More interesting, perhaps, than who will finally buy Twitter could be the question of whether Google is reopening the acquisition spigot. The company has been aggressively managing its capital expenses to keep the earnings looking as good as possible in the downturn, but perhaps the Twitter acquisition wouldn't be big enough to signify a comeback.

UPDATE: Ad Age yesterday noted that Google's already using Twitter, without buying it - advertisers can pay Google to redistribute their 140 character tweets so they reach beyond Twitter's 7 million users.

Even better is the ad mag's take on tweets and other new media jargon. Perhaps investors read that March 30 piece and decided it was time to get serious about selling.