Danish artist Mads Lynnerup's seminal photographic masterpiece, Untying A Shoe With An Erection. The first of his Working Erection series, which encompasses many similar works of limpid artistic genius like Erection Functioning as a Metronome, Conducting A Symphony With An Erection and my personal favorite, Erection As A Pogo Stick.
Please click the image above to see it as it was meant to be seen: animated.
Mads Lynnerup [Artist's Site] (via Vvork)
