Popcorn!

Once upon a time, I learned that there are different types of popcorn out there. It isn't all just the white kernel stuff you salt and butter. It comes in different sizes, colors, and even tastes very different depending on the type. However, whenever I try to search for that kind of stuff, I get sent to sites for caramel corn, etc. I'm on a bit of a popcorn kick, and thought maybe it'd be fun to try other natural varieties. Does anyone have any links to either information, or a place I could look around and see what types I could purchase?

Thanks in advance!