Drag & Drop mails into Tasks! Rated 4 out of 5 stars
I've long dreamed about being able to take an email and turn it into a task just by dragging and dropping, and this lets me do just that! It also has a thoughtful visual interface that shows you which mails are linked to which tasks, and vice versa. All in all, very convenient and well thought out!
Just a couple of things need work: the link between a task and an email gets broken when I move or archive the email on an IMAP server. Parts of the interface are clunky, such as moving from a mail to a task or vice versa, and the English manual is confusing and needs editing. But I'm sure this will improve with time, and it will only make a great extension even better. I'm already an addict!