I've been on Wikipedia since the spring of 2006, and have generally edited pages involved in Track and Field, space flight and fringe belief issues, such as ufos and the North American Union. In terms of creating a page, I did a lot of work writing the Carl Lewis biography, (though it has been messed up recently) initiating the complete re-do of the Roswell UFO incident page and sister pages, and have been lately (Summer 2009) adding a lot of detail and citations to many of the Soviet space flights of the 1970s and afterwards.
I've done some work on the JFK assassination pages, and have waded into the mire of the North American Union pages. In both cases, there is a lot less to the eye, despite what some in the conspiracy communities say, IMHO.
I have a deep interest in track and field/athletics. I have added a lot of biographical information on various runners, particularly late 19th and early 20th century record setters in the mile. Typically, I have insufficient information to make these pages little more than glorified stubs, but it's a start.