This works with the site yubnub.org. First highlight some text, then click the bookmarklet. A dialogue box pops up to ask the YubNub command to be used. It then performs that command on the highlighted text.
1 2 javascript:q = "" + (window.getSelection ? window.getSelection() : document.getSelection ? document.getSelection() : document.selection.createRange().text); p = prompt("Yubnub search type? ... ", ""); if (q!=null) location="http://yubnub.org/parser/parse?command=" + escape(p).replace(/ /g, "+") + " " + escape(q).replace(/ /g, "+"); void 0