Thanks for all the replies... Have him move back home with stipulations attached to his stay was my choice as well.

I was just wondering if any other parent would have chosen one of the other three choices over having him move back home as I was told, by son's gf, that I made it to easy for him when he left and it was suggested that I could have done any of the other three things before I allowed him to just come back home.... in other words I am enabling him to continue to be the way he was before he moved out (per gf words: no job, argumentative, and lazy).

I on the other could not just sit by and allow my son to live in a car when we have a perfectly good house here in the same city... and I thought with me being home that I could help push him into getting a job or at least look for one in this economy.
P.S. --> he does have a small past that is haunting his attempt in finding a permanent job - some thing from his youth form one of those stupid mistakes some people make between leaving home and growing up.