I have to use Thunderbird for work email. I've been an avid Toodledo user for a couple of years now, however the absence of a means of linking a task to the email in Thunderbird that generated that task, and to which I will have to reply, has always frustrated me. ThunderLink provides an easy means to do just this.
I think ThunderLink is such a useful adjunct to Toodledo that I think you should include a link to it in your third-party tools section.
Now for the related improvement request: the ThunderLink URL that I include in a task's note does not get automatically converted to a clickable link in the way that you automatically convert http links. Please could you generalise your link conversion to any URI, or if that is too hard, specifically for thunderlinks, i.e. links of the form "thunderlink://messageid=nnn"?
Firefox lets me right click on the thunderlink and launch it in a separate tab or window, however a simple normal click on a hyperlink would be more convenient.
And finally, thanks for Toodledo. I would be lost without it.