The answer changes practically every week. But as of today, here’s the answer.

My current desktop system is a Windows 7 64-bit 8-core machine with two large displays, arranged so they don’t obstruct the nice view out of my office windows. (The machine is in a different room so I don’t have to listen to its noise.) I have a large Linux file server, and various compute servers etc., in a server room in the basement.

(I have a long history of using different types of computers; as of 2002, the list is detailed here).

Around my house, I just switched to using a 15″ MacBook Pro as my portable computer. Outside the house, I had been using a Lenovo ThinkPad X301 running Windows 7 with a cellular modem, but I’m now switching to a MacBook Air with a MiFi device. When I give talks, I sometimes connect a small side monitor, that I use to pick slides to answer questions with.

I currently use an iPhone 4 as my main mobile phone, and I’m now carrying an iPad 3G around to use as my instant-on system. (I was recently on a vacation that involved some beach time with direct sunlight, during which I used a Kindle — in a plastic bag to avoid the sand.)

For many years, I’ve gotten devices and gadgets as soon as they come out (and sometimes before)… and some I continue to use. I also have all sorts of computers, phones, etc. that I use to try out Mathematica and Wolfram|Alpha on. Occasionally, I’ll connect to one of the large compute clusters we have at our company, and use gridMathematica here.

Among other hardware, I have a computer set up to use while walking on a treadmill. (I can type reliably up to about 2.5 mph.) I also have a fairly elaborate videoconferencing room. And my house has all sorts of computerized sensors and controls.

Recently I tried using a telepresence robot from Anybots.