Sleeping with your head rotated all the way around and your eyes half open is probably a policy more of us should follow.
Birds are cool; they can sleep on one side of the brain while awake on the other! http://en.wikipedia.org/wiki/Unihemispheric_slow-wave_sleep
...especially while sleeping standing on a railing, with a ferry heading your way (just ask John Roebling about those ferries).
This immediately reminds me of Fernand Khnopff's "Sleeping Medusa": http://pinterest.com/pin/143059725633386724/ .
Shame they don't always come with a woman's head attached.
I love pelicans.