Gap Kids have a nice selection of lunch bags at the moment... $14.95. the 'peg is a little loose in it, but extra padding (a sandwiche or 2) would solve that. No strap, so people wouldn't have any concerns about your sexuality.
There's a rugged camo-pattern for the would-be survivor, a neutral black & gray for the suave and sophisticated types, and a rather fetching pink and white number for those who want to present their sweet innocence to the world. And a quite garish blue and orange affair too, but we wont go into that one.
But kiddies, remember to label you lunch pack clearly in
BIG LETTERS. You would want one of the other kids to grab your lunchbox by mistake in the playground.