You don't have to sneak your snacks (or contraband Pepsi) into the parks anymore--as of December 2008, bringing in your own food is no longer prohibited. While this policy was never really enforced, being allowed to bring in lunch or snacks eases the shame those of us with highly developed super-egos feel when breaking the rules, one guilt-ridden Cheeto at a time. It also means that those who follow a special diet or who are trying to save pennies while vacationing can bring their own food without worry. This is a welcomed change.
Coolers, glass containers, alcohol and items that need to be heated are still prohibited. Also, microwaves, barbeques, half hogs, and Grandma's favorite cast iron skillet.