Forwarding this link from the BromptonTalk group - thought this might amuse and inspire a new direction in winter bike mods.
(more pics after the jump)
Whoa! If I ever get another Birdy, it will definitely be NOT to convert it to one of those! (That's what a DT is for! )
See upper right photo in http://oddwidget.com/~mnhpva/ice/ice2002/Ice4.html for another option.