I'd like to see the "who's online" section of the sidebar be done like a plugin, or at least a file like bloglist or linkblog are done so that it would be easier to customize the tagging and text it currently gets. Currently to get away from an unordered list, or to give it my own unordered list class, I have to replace "$Sessions->display_onliners();" with a pair of functions and feed it appropriate parameters.