I actually had the same issue when I lived in Noe Valley. I'd suggest hunt around on Craigslist. Depending on how picky you are with location (I was pretty picky because I was on a hill, so I had a bit of a hard time finding something within a couple of blocks), you should be able to find several available spots at any given time. However, just be aware that they tend to rent between $300 and $350 a month.
Hope this helps!