You could try some of the EnviroKidz bars (the non-peanut butter flavors). They say they could contain traces of nuts, though, I'm sure because the peanut butter flavor is processed on the same equipment.

Fig Newtons are wonderful, but they can get squishy in a jersey pocket. Jelly Bellys are fun, but sometimes tasted too sweet on hot days. You might even be able to make your own trail mix without peanuts.