The European Space Agency is looking for volunteers to spend 520 days isolated a Moscow facility where they'd simulate traveling to, living on, and coming back from Mars. Not bad, except the pretend travel lasts 250 days each way.
There are plenty of necessary qualifications to meet including fluency in Russian, background in medicine, various engineering, and for whatever reason you may not be taller than 185cm (that's just under 6'1"). Interested? Apply on the ESA website. [ESA via PhysOrg]