Is your son going to San Jose State University, by any chance? It's a great school and my home town is not far from there. If you are looking for affordable housing in and around the university, the school will have some housing options both on-campus and off-campus. Contact the housing office and ask them. Also try sfbay.craigslist.org (some of the listings there may be a bit pricey, and you will also have to check for South Bay listings rather than something in San Francisco). Check out the classified sections of the local papers, especially www.mercurynews.com and even try checking is some of the areas near San Jose, like the Fremont Argus newspaper www.insidebayarea.com/argus