If you look at companies with upside potential, Twitter's right there. They've established a brand in a world where it's extremely difficult to establish a brand. It's a global brand, people recognize it, people want to let you know what their Twitter handles are, etc.

It's always great when you get a lot of people pushing themselves to do better, be better, invent better, better serve, better lead customers in new directions.

I've found three or four things that are quite interesting to me that I'm focused on. That's been fun.The Clippers is obviously one of them.

The company I invested in is probably a leader in that area. They're a company called Second Spectrum, which happens to be based in LA but was started by two USC computer-science professors. It's filled with guys who love sports, who played sports, but really look like programmers.

Not only because the product wasn't a great product, but remember it took us five or six years to ship it. Then we had to sort of fix it. That was what I might call Windows 7.

I want to express my deepest condolences at the passing of Steve Jobs, one of the founders of our industry and a true visionary. My heart goes out to his family, everyone at Apple and everyone who has been touched by his work.

At Microsoft, we're investing heavily in security because we want customers to be able to trust their computing experiences, so they can realize the full benefits of the interconnected world we live in.