Just got back from WDW last night. A small gelato is considered a snack credit at CSR - and it's delicious! They have 10 flavors to choose from, we had mango, raspberry and chocolate hazelnut, yum!
Someone had asked about snack credits at Wide World of Sports. They aren't very organized there, and hopefully that will change when they become the ESPN world of sports (or whatever the new name will be). Basically just a cookie, soda, water, or chips. Possibly popcorn too, but they don't sell that at the regular CS stand, you have to go to a separate stand out by the baseball fields. Good luck.