What to do on my day off?

I have the day off today and its weird because I don't normally have one during the week unless I am sick, but I do. Jarrett has a doctors appointment in an hour and a half to check his TB shot and normally he would be in daycare today, but he is playing hookie with mommy! What to do with him today? Its kind of chilly outside for California weather. I was thinking the park, but after the park where else to take him. Any suggestions? I want to make hookie day count!