Cloud storage company Dropbox is now valued at about $4 billion according to a rumor. This is based on an investment round led by Index Ventures. Supposedly some venture capital firms even considered giving Dropbox an $8 billion valuation. Dropbox was founded by MIT graduates Drew Houston and Arash Ferdowsi as a Y Combinator startup. Dropbox’s 2010 revenue was estimated to be around $100 million. [TechCrunch]

Groupalia, a European online group buying company, has raised $26 million in funding. The startup’s investors include Nauta Capital, Caixa Capital Risc, General Atlantic, Insight Venture Partners, Index Ventures, Lucas Carné and José Manuel Villanueva. The daily deals company is just two years old and has 10 million users. [TechCrunch]

A few days ago I wrote about how Google and Facebook were in talks to form a partnership with Skype. Looks like those talks have ended because Microsoft is going to acquire Skype Technologies Inc. for between $7-$8 billion according to several sources. Including the long-term debt associated with Skype, the deal is worth about $8.5 billion. This would be Microsoft’s largest acquisition since Yahoo! turned down the $48 billion offer.

Big Switch Networks has raised $13.75 million in a first round of funding. Big Switch Networks is working on building a platform that will bring virtualization and a cloud architecture to enterprise networks. Four new directors will be joining the board at Big Switch Networks as a result of the funding: Mark Leslie, Bill Meehan, Shirish Sathaye, and Mike Volpi. The investors in this round include Index Ventures and Khosla Ventures. [San Jose Business Journal]

OpenBuildings.com has raised $2 million in a series A round of funding led by BlueRun Ventures and Index Ventures. John Malloy (BlueRun) will be joining the board of directors at OpenBuildings.

Flipboard CEO Mike McCue has confirmed that the company has raised $50 million at a $200 million valuation. Insight Venture Partners led this round of funding. “We’re obviously thrilled, because we think it confirms our focus that people want a beautifully designed way to interact with content and to share it,” stated McCue. “And there is a lot more to come–on a scale of one to 10, we’re just at a two or three.”

Groupalia is a Spain-based group buying website that has raised $15 million from their current shareholders and new investors. Investors in this round include General Atlantic, Insight Venture Partners, and Index Ventures. Like Groupon.com, Groupalia has a daily deal in the form of discount coupons and they are expecting to turn over about $150 million in 2011 revenues. The extra funding will be used for consolidating their position in the countries that they are already established in. Groupalia has about 6 million users, 400 employees, and is present in 8 countries. [TC Europe]

Social media reading application company Flipboard is raising funding that would give them a $200 million valuation according to sources with AllThingsD. The valuation is subject to change. Flipboard was co-founded by Mike McCue and former Apple iPhone engineer Evan Doll. When Flipboard launched in January, they had raised $10.5 million in VC funding from Kleiner Perkins, Index Centures, Jack Dorsey, Dustin Moskovitz, Ron Conway, Ashton Kutcher, and Peter Chernin. Flipboard has zero revenue thus far. [AllThingsD]