Know what's cool? Take a couple of slices of Wonder bread and your favorite filling. Spread the filling on one slice of bread, leaving about a 1/4" to 1/2" margin around the edges. Put the other slice on top and then use the edge of a fork or the back edge of a butter knife to pinch the two slices of bread together at the margin point and to cut off the crusts. This should leave you with a completely sealed bread pocket.
Japanese stores sell these at 2 pockets for 100 yen ($1), with fillings that include peanut butter; apple jelly; strawberry jam; and maple syrup and butter. Follow the link and click on "Enter" to view the full selection of "lunch packs".