My contributions to Wikipedia content at this point have been fairly small, including simple typo corrections, grammar corrections, and the resolving of an occasional contradiction. I'm very good at finding sentences and paragraphs that I think should be removed, much worse at actually taking on the task of writing them.
Update: I'm upgrading myself to a "Discussion Junkie". I have a tendency now to elaborate endlessly on the shortcomings of various articles, without doing much actual editing. I also have the tendency to do so on controversial pages, where I hardly bother to read through the existing discussion. I'm increasingly of the opinion that wikipedia is severely in need of a new discussion format, the current "append babble indefinitely" method does not work well. We need more structure, especially so that the same thing isn't argued over and over again, and so that topics that descend into nonsense can be filtered out, without necessarily removing the original topic. Obviously, this could be done with the current technology, but it would be easier to program it to work a good way than to just tell people to edit the discussion page a certain way.