You can do LOADS with chestnuts, they are ace! Here are some ideas:
Chestnut stuffing. I use a Nigella recipe, here: newnigella127.blogspot.com/
Marrons Glaces. A bit time-consuming, but they are very expensive in the shops, so worth it if you like them! Also makes a lovely gift, and they store very well. I just googled a recipe here: www.epicureantable.com/recipes/C/chestglace.htm
You can store them in a jar in their syrup for months, and then put them in individual mini muffin cases or something when you are ready to serve.
Chestnut flour - very gourmet stuff, you cook the chestnuts as described by cogito and then grate them, and then dry them out in a very low oven. The resulting flour is very rich, and you can use it to make really fancy pasta (replace half the flour with it in a normal pasta recipe) or a really rich roux sauce, or biscuits or pancakes etc etc etc.
Have a look at the River Cottage Hedgerow handbook, which is where I got most of my ideas from. You can also make chestnut and chocolate jam, although I've never made that and can't remember the recipe (it was in the River Cottage preserves handbook).
Also: Chestnut and chocolate cake!