This plugin adds up to four new buttons / links to the WordPress Editor panel. You can select to add a quicktag to easily insert: 
Amazon item links 
Amazon product searches 
custom span class 
custom div class
The settings pane allows you to enter defaults, as well as your own Amazon associate ID.

David’s Ultra Quicktags

Adds new buttons to the Editor window (Amazon Links, Amazon Search, etc.).

bmsterling

This plugin adds more buttons to the non-visual editor view for creating/editing posts/pages
Currently adds: 
* h1 
* h2 
* h3 
* h4 
* h5 
* q 
* cite 
* sub 
* sup 
* dl 
* dt 
* dd
<h3>Credits</h3>
Copyright 2012 Benjamin Sterling (benjamin.sterling@kenzomedia.com)
This program is free software; you can redistribute it and/or modify 
it under the terms of the GNU General Public License, version 2, as 
published by the Free Software Foundation.
This program is distributed in the hope that it will be useful, 
but WITHOUT ANY WARRANTY; without even the implied warranty of 
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 
GNU General Public License for more details.
You should have received a copy of the GNU General Public License 
along with this program; if not, write to the Free Software 
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

Quicktag Extender

This plugin adds more buttons to the non-visual editor view for creating/editing posts/pages

David’s Ultra Quicktags vs Quicktag Extender