Genius Thunderbird plugin that sets a custom From address based on the recipient address of the email. Genius, exactly what I've been seeking for years. Now to get it setup...
The Magento plugin / extension recommended by the Varnish publishers, albeit in a blog post in September 2012.
Article from Varnish Software about magento plugins, recommends the Phoenix one...
Jetpack is a simple language to write almost on-the-fly Firefox plugins. Pretty amazing technology, looks like css / jquery with some custom methods. Beautiful. Hat tip sfllaw.