Working in SF this Summer. Looking to Rent or to House Sit

Hi,
I'm working for a startup company this summer from June 24 until Sept 1 and I'm looking for an affordable place to live in SF or near SF. My name is leonardo and I'm majoring in Economics at Stanford University.
I was born in Mexico and I have lived in the US for 7 years. I speak English, Spanish, French, Italian and basic chinese.
Please let me know if you need a roommate.