I haven't really done much, but I try to correct problems with facts whenever I come across them. One thing I truly hate is advertisements, for instance the one I corrected on the "rockcorps" page
Recently I've made a few minor changes on NPOV issues (i.e. Grammy Article). The largest change I've made is on the page for indie pop-punk band The Thermals page. I discovered the history section had been directly plagarized from the thermals' own website. After no one responded to my question/request for a change on the discussion page, I decided to go ahead with it myself, completely rewriting the history section using respected sources.