Make your own Firefox sidebar

It's easy to make your own Firefox sidebar, and all you need to know is HTML!

For example, here's mine: http://members.shaw.ca/Jon_Aquino/Bookmarks.html

1. Make an HTML page (a narrow one, mind you -- it is a sidebar after all).
2. Bookmark it in Firefox
3. Open the Properties for your bookmark and click the Load This Bookmark In The Sidebar checkbox
   

My sidebar is filled with bookmarklets. I prefer bookmarklets to plugins, as they keep my work and home browsers in sync; plus I can access them from any computer.