The site breaks the freebies down by adult, child, pets, and state. Perfect! You can also search by type of freebie (travel, entertainment, food, and retail). The online category does not seem to have any entries, unfortunately.
Adults in California, for instance, can get a free car wash at 7 Flags, free skiing at Big Bear, and a lot of free food. If you know of a deal that is not listed, add it here.