Really Arty Posters

Have you see Flight of the Conchords? I'm a new fan of the show (for their ode to love and stationery supplies, click here.) They recently hosted a "Really Arty Poster Contest" and the submissions are quite outstanding. It seems that many talented people entered the contest because I browsed through all 375 entries and the majority of them were good-quality poster designs. (Here's the winner.) Is there something about the show that particularly appeals to designers and illustrators? Might it Brett's animal t-shirts?