Cool Firefox Add-ons

Here's a good one for Google bookmarks:

This plug-in will save your bookmarks to Google bookmarks from your Firefox browser and vice-versa. It has a very neat search/managing utility and elegantly fits right in the upper menu.
Enjoy:

https://addons.mozilla.org/en-US/firefox/downloads/file/21602/gmarks-0.9.7.3-fx.xpi

Cool Thunderbird Add-ons

Here are some cool Thunderbird add-ons I found, note I have Thunderbird 2.0+

Check all your emails at once:
https://addons.mozilla.org/en-US/thunderbird/downloads/file/22015/get_all_mails-1.0.5-tb.xpi

Double checks your "To:" spelling, your usage of predefined words and spelling, and asks if you are sure to send (because let's face it, it can be embarrassing even if it's only to us)"

https://addons.mozilla.org/en-US/thunderbird/downloads/file/21453/check_and_send-0.7.40-tb.xpi

Removes this crap ">>>" from emails, inelegant indentation especially when I want to neatly paste parts of my recipients message in a reply-to:

https://addons.mozilla.org/en-US/thunderbird/downloads/file/16450/nestedquote_remover-0.7.18-tb.xpi

Pastes formatted code with colour into an email, haven't tested it but I like the concept:
https://addons.mozilla.org/en-US/thunderbird/downloads/file/15996/pastecode-0.6.1-tb.xpi

Shows the address in your email header, no need for right clicking in case you're not into that:
https://addons.mozilla.org/en-US/thunderbird/downloads/file/14821/show_address-0.0.4-tb.xpi