I mostly use the source editor over the visual editor, but use the latter for referencing and I use ProveIt for citations, as I'm not too good at using the templates. I joined Wikipedia to try and improve the article Gulval. I am currently creating an article on Dingle Farm Tearoom, although I am on-and-off with this.
Bookmarklets are Javascript programs that are stored as bookmarks in your browser, and which run when you click on them as opposed to bringing you to a page like a normal bookmark. Here is one that conducts a search in Wikipedia on any text you happen to have highlighted in whichever window you are in (or if no text is highlighted, presents you with a popup search box): ~axel/bookmarklet.html. See also Bookmarklets.