I was working for a software company in the north bay. I spent most of my awake time at work and most of my weekends in the mountains or visiting my girlfriend in LA.
I realized I was spending a large sum of rent money for an apartment I was never in, except to sleep.
So I got a storage unit to hold my few belongings, got a service I could drop my laundry at (I hate laundromats) and started sleeping in my car. Work had a shower so that wasn't a problem.
Most nights I parked my car on the street near an apartment complex not far from the Golden Gate bridge. In six months I only got hassled by the police once and I just told 'em I worked at said software company in Sausalito and had drank too much that night and didn't feel it was safe to drive home (giving the address of a co-worker who lived further north I had an agreement with for this situation). They said fine and suggested parking somewhere else.
Eventually I got a new girlfriend and being homeless just wasn't practical so I ended up renting a room from a friend. I sured saved a lot of money during those 6 months, though.