Fight car culture while sitting on your ass in sprawling Cal Anderson Park. The second-annual Northwest Film Forum Bike-In will feature films (learn how to bike safely on city streets!), live music (including adorable local band Boat!), a potluck, bike-friendly businesses, bike art, bike valet parking, and more. (Cal Anderson Park, 1635 11th Avenue, 267-5380. 5 pm, $2 donation.)