Ask HN: What Silicon Valley startups accept temporary workers?

Hello HN, I've just graduated from a technologist course from UTFPR (Federal Technological University of Paraná, Brazil), I'll stay in Palo Alto between 09/29 and 12/05. During my stay, I'd love to work at a startup! I want to experience how it works, how problems are solved, learn and have fun. I have some experience with PHP, JavaScript (jQuery) and MySQL, but I'm interested in doing anything a startup need. I'm not focused in getting paid, since learning and helping are my objectives, but anything would be helpful during my stay. Please recommend me startups that have this interest as well. Thanks!