Do you want a 7 KB cross-browser native JavaScript that makes your plain HTML lists super flexible, searchable, sortable and filterable? Yeah!
Do you also want the possibility to add, edit and remove items by dead simple templating? Hell yeah!

https://github.com/javve/list

Example of a "Toolbar" bookmarklet

Example of a "Toolbar" bookmarklet

javascript:(function({
  var INSTAPAPER=true,w=window,d=document,pageSelectedTxt=w.getSelection?w.getSelection():(d.getSelection)?d.getSelection():(d.selection?d.selection.createRange().text:0),pageTitle=d.title,pageUri=w.location.href,tmplt="";
  tmplt="From ["+pageTitle+"]("+pageUri+"):\n\n";
  if(pageSelectedTxt!="") {
    pageSelectedTxt=">%20"+pageSelectedTxt;
    pageSelectedTxt=pageSelectedTxt.replace(/(\r\n|\n+|\r)/gm,"\n");
    pageSelectedTxt=pageSelectedTxt.replace(/\n/g,"\n>%20\n>%20");
    w.location.href="nvalt://make/?txt="+encodeURIComponent(tmplt+pageSelectedTxt)+"&title="+encodeURIComponent(pageTitle)
  }
  else {
    if(INSTAPAPER) {
      pageUri="http://www.instapaper.com/m?u="+encodeURIComponent(pageUri)
    };
    w.location.href="nvalt://make/?url="+encodeURIComponent(pageUri)+"&title="+encodeURIComponent(pageTitle)
  }
})();

JavaScript to test each CSS class on a page and report which are hindering performance

A faster way to add bookmarks to Del.icio.us, in the style of Instapaper's bookmarklet. Watch the demo screencast: http://vimeo.com/3358711

A faster way to add bookmarks to Del.icio.us. Written by Garrett Murray.

FEATURES

It's fast! Add a page to Del.icio.us without having to fill out any forms.
If you select text on the page you're about to bookmark, it will automatically be added as the notes for the mark.
All bookmarks added with quickbite will be tagged "quickbite" allowing you to quickly view everything you've added via this tool.
INSTALL

quickbite requires you have cURL support installed with PHP. Most hosts do.

Add appropriate settings in conf.php
Upload quickbite dir to your server somewhere
Generate your bookmarklet by visiting the location you uploaded to + /bookmarklet.php
DELETE OR RENAME THE bookmarklet.php FILE TO SOMETHING CRYPTIC! THIS IS VERY IMPORTANT!
You're done!

UPDATES

Code is hosted at GitHub: http://github.com/garrettmurray/quickbite
Author writes nonsense at Maniacal Rage: http://maniacalrage.net