Check Out the Aeolus Airship: Human-Powered Blimp Can Stay Aloft for Two Weeks
Setting the bar pretty high for airship design is this one from Christopher Ottersbach: Called the Aeolus Airship (named after Aeolus, the Greek wind god) it is designed to be aerodynamic than conventional airship designs, and stay aloft for up to two weeks on a supply of helium and, furthermore, is pedal-powered by the crew of 2-4 people. That's about all the tech detail I've come across; it's certainly made the rounds in the past couple of days but no specific website or contact info seems forthcoming. Christopher, I'd love to talk to you if you come across this.
In any case, here are lots of cool photos of this sleek new human-powered aircraft: