Rated 5 out of 5 stars

I love it. Adds some great functionality when taskbar space is precious.

I've updated it to be a "2.9" version which works wth Thunderbird 3.0 alphas. Works as intended for me.

Just open the XPI in WinZip or WinRar and edit install.rdf where it says "2.0*" to say:
3.*

Works like a charm :) Don't forget to re-zip up all the files and rename it to an "xpi" file and install it.