Oprah Winfrey is about to take Twitter to a whole new level. The talk show host is scheduled to do her first "tweet" on-air tomorrow. Guests include Ashton Kutcher, who is racing CNN to the one-million Twitter follower mark. Was this what Twitter co-founder Evan Williams was talking about in his mysterious reference to a "big day" tomorrow? I just checked out Oprah's Twitter account, which already has more than 38,000 followers, despite having no updates yet. Oprah, if you recall, gave a big plug to Amazon.com's Kindle electronic reader last year, which led to a sell-out of the device.

Speaking of Kindle, TechCrunch comes up with some sales numbers for Amazon's second-generation Kindle 2, which started shipping in February. The blog, quoting a source close to Amazon, says Kindle 2 is "selling at roughly double the rate of the first generation device" and has shipped 300,000 of the devices, suggesting more than $100 million in revenue.

Seattle-based HomeSavvi, a website connecting home remodelers with products and services, is expanding its geographic footprint, moving into Atlanta, San Francisco, and Portland, Ore. People in those cities can use HomeSavvi to connect with "local contractors, architects, interior designers and retailers to develop and budget exactly the right project," the startup said in a release.

One of Seattle's nonprofit research powerhouses, the Fred Hutchinson Cancer Research Center, said it will lay off 83 people, representing 3 percent of its staff. The center said the financial crisis has “significantly reduced philanthropic giving and investment income.”