In California, I gave the landlord a verbal notice that we were vacating on the 24th of the month prior to our last month. Landlord said I had to give written notice 2 weeks later. I filled out the form and turned it in... landlord said she would not accept it as both tenants must sign the vacating notice. My roommate (we are students) graduated and is traveling. I cannot get ahold of him. Am I stuck until I can get ahold of him and get him to sign the document?

Yep... both of you are on the lease you both have to sign it.