Linking to E-mail Messages

Via Lifehacker: Bookmark Your Email with Gmail or Mail.app. Unfortuantely, I don't use Gmail or Mail.app, the former because I don't like being tied to specific vendors, and the latter because I can't deal with its message threading. I've been searching for a way to do this with Thunderbird (my client of choice) for some time now. Maybe this will inspire some Thunderbird hacker to implement the functionality.