Dip the top of the banana in the chocolate, then roll it in crushed nuts. Leave to set for half an hour then carefully replace the fruit in the banana peel and freeze. Choc dips Strawberries can be dipped in chocolate, too, before they are frozen. Slices of really ripe pineapple can also be dipped in chocolate. Just dip one half so that the other half can be easily grabbed by small fingers without getting brown smears everywhere.
Frozen fruit keeps reasonably well.
If you decide to have your own teddy bear's picnic, place a few frozen 'bricks' in the esky, and wrap each piece of fruit in aluminium foil before freezing the night before. Take out everything just before you leave and, with luck and good management, it should still be frozen a couple of hours later. Remember, the more frozen fruit you take, the longer it will all keep cold. A few pieces thaw much faster than 50, which is a great excuse for pigging out. Or just have the picnic at home, under the pergola or on the back steps, which is a great place to contemplate the world.