OpenUp is a simple Thunderbird extension I'm developing to implement the GTD in Thunderbird itself.

At the moment, it provides two features:

• opening the containing folder of a message (useful when you're looking at a message from a saved search);
• tagging a message when sending out (not available up to TB 3; useful to add a 'waiting for' tag to outgoing messages.

The project is still in alpha state; new features I want to add:

• adding a folder to all my saved searches when I create a new folder (at the moment, I've to work on all of them by hand);
• creating a message and saving it in the currently selected folder.