My Cookbooks Online

A good idea... this site searches the cookbooks that you already own, works out which recipes you can make and in what quantity, then gives you a personalised shopping list so you can hit the shops.

You need to sign up for it, but I think that if you are the kind of person who really can't be arsed trolling through your cookbook library for every little thing (preferring instead to search online...like I do) then this could be a godsend. Just tell it what books you have and it will make your life easier. Can't argue with that.