In early October I rented out a bedroom in my house (no lease was signed). A couple weeks later, the guy went home for a couple weeks due to an emergency (home is a few hours away). Before the end of October, he called to tell me he was staying at home for another week or so, but he'd be back by 10/31/08 so he could pay November's rent. Well, 10/31/08 came and went, I called his cell a couple of times since then.. . Which went right to voice mail. I have not received a return call. So here it is about 6 weeks since I last communicated with him. It all seems very strange to me. My question is, how long must I retain his belongings before I can legally dispose of them?

I think you would have to go through normal eviction procedures as they are applicable in your state. After the procedure is over they give a set number of days for the tenant to leave, once that time is up you can toss out his stuff.