When I was a junior in college, my hatchling female got out just before Thanksgiving. I lived on the third floor of my dorm. I ripped up the carpet, took apart the wall heater, etc. several times looking for it and finally after about 2 months, just gave up. I informed all the residents of the hall that I knew (including the Resident Assistants and Directors) and asked them to keep their eye out for it.
Two weeks before summer break (mid May) I got a call at 1:30 am. It was a drunken friend who lived on the second floor. He said that he found the snake and to come get it. I hurried over (took me about 1/2 hour to get there, as I was at my girlfriends apt.) to find that he had left, but his room mate was there. I told him that there was a snake there for me to pick up. He immediately jumped up on the coffee table and began looking very freaked out. I found a cardboard box with big knife holes in it and knew instantly that the snake was once in there but not any more. I began frantically searching the room, thru dirty clothes, under stuff, and eventually found her behind the couch. My friend had stumbled upon a drunken couple in the stairwell that were attempting to break in the basement (probably to do naughty things), that had discovered the snake and were about to smash it's head in with a high heel shoe because it looked venomous to them. He knew immediately that it was my snake and saved her for me. She was gone for 6 months, presumably hibernated over the winter, probably hadn't eaten a thing, and was suprising healthy looking.
So the take home message is not to give up, your snake will probably turn up sooner or later. The best thing that could happen (besides you finding her right away) is that it will simply find a nice dark spot to hibernate for a few months.
SSSammy
Mike