Jimmy "Jimbo" Wales, the founder of www.wikipedia.org, speaking at FOSDEM '05 in Brussels, Belgium.
A high res version of this photo can be found here (3504x2336, 2447 KB) - and is licensed under a Creative Commons - Attribution Sharealike 2.0 license. If you use it, please credit me (as detailed in the license) and drop me a line and let me know where it's being used.
Update: This photo has been seen on www.newscientist.com/channel/opinion/mg19325896.300, ValleyWag, TheAge, and at a Wikipedia Conference in Taiwan
Update2: I was contacted by Guinness World Records in London who will use this photo in the 2008 book.