Oh, this is one of my favorites! (OK, I say that about every festival.)
It's a lot of fun, though. The World Food Festival is located in the East Village of Des Moines, and it's free to get in. There are vendors from almost every country represented, and every one will have some awesome little tastes for $1. You can get full meals for much more, but it's so fun and yummy to go around and try a little of everything.
My favorite "new" thing last year was from Bosnia, but we also got to try a lot of old favorites. I just counted 66 different food vendors on the list for this year! They also have a lot of great free entertainment. You can check out the free entertainment schedule here, and get all the pertinent details here.
Hope to see you there!