SAN FRANCISCO - APRIL 14: Attendees mingle during a break at the first annual Chirp, Twitter Developer's Conference April 14, 2010 in San Francisco, California. Chirp, the Twitter Devloper's Conference is a two day event for developers who work with the popular social networking service. (Photo by Justin Sullivan/Getty Images)
Google is said to float $2.5 billion as a good starting point; Microsoft thought $4 billion was a nice, round number, apparently.
Now these were not formal offers, we're cautioned, but neither was Southwest Airlines when Herb Kelleher sat down in a bar, grabbed a napkin, grabbed a pen and -- bing -- the disruptive carrier was born.
Of course, with the way Silicon Valley brains move about, these -- and many more companies -- talk all the time. Still, with Twitter seeking a higher valuation, the two giants will surely be involved should "the Tweeter" be floated as attainable.