A collection of plugins by Stephen Kimmel, including a number of additional editor toolbar buttons.
http://skplugins.tiddlyspot.com/
In keeping with the general spirit of the TiddlyWiki community, ie, you develop something useful and/or potentially interesting you share it with others, I'm sharing some of the plugins I've developed to go with the new Editor Toolbar. You'll find them and a more extensive discussion of what each does at http://skplugins.tiddlyspot.com/