It's a tablet! It's a skateboard! Steven Sinofsky holds a Surface tablet during Microsoft Windows 8 event in 2012

It’s been quite a week for Steven Sinofsky, who ran Microsoft’s ginormous Windows division for three years before bowing out in late 2012. After ensconcing himself at Harvard Business School’s leafy confines for a time, Sinofsky is suddenly all over Silicon Valley.

First, Sinofsky announced that he’d be joining venture capital “it” girl Andreessen Horowitz as a board partner. As I wrote about a while back, that’s essentially a part-time job that involves advising Andreessen portfolio companies. Yesterday, Sinofsky blogged that for his first trick, he’d be overseeing a new, $6 million investment in a Burlingame startup called Local Motion, which is bringing the car-sharing craze launched by companies like Sidecar and RelayRides to corporate and government fleets.

The pixels had barely dried on that announcement when Box — the Los Altos file-sharing startup that’s perhaps the hottest name right now in the Andreessen stable — today slapped together a blog post with news that Sinofsky was signing on as an advisor. With Box very obviously chugging down the IPO track, pundits have fallen over themselves to praise the move, noting that Sinofsky’s skill set is exactly what a company like Box needs as it hopes to upset entrenched enterprise software companies like, oh, say, Microsoft.

Interestingly, Sinofsky’s name was already listed among the speakers at next month’s BoxWorks conference. Also on the slate? Former Washington, D.C. Mayor Adrian Fenty — who, aside from reportedly dating Steve Jobs’ widow, is also an advisor at .. Andreessen Horowitz!

Peter Delevett Peter Delevett (184 Posts)

Peter Delevett covers startups and venture capital for the San Jose Mercury News. He's been a journalist in Silicon Valley since the dot-com daze.