I read about this website in my local paper (the Boston Globe) and have been playing with it for the last few days. It's a great and easy to use website on finding recipes from all your cookbooks. There is a free 30 day trial and a limited lifetime membership for $50.
I don't have nearly as many cookbooks as most HC hounds. I use about 25 of them regularly but do spend way too much time going through them, looking for recipes using certain ingredients. Since I have a summer, winter and meat CSA, I spend a lot of time backtracking through cookbooks. This site is a huge time saver.
You input your cookbook titles into the database. EYB has a huge database of indexed cookbooks. Then, to do a search, you go to your library and type in an ingredient. The site then goes through your library's cookbooks, and matches ingredients to the recipes you already have.
Where this will really get interesting is when I input the cookbooks that I don't use on a regular basis. Who knows what interesting recipes will pop up when I type in an ingredient I want to use up. There are cookbooks on the back end of my shelf that I never look at and this can help remedy that.
NOTE: the site doesn't show the recipe, it just tells you what cookbook it's from. This way, you don't have to comb through all your cookbooks to find recipes for whatever excess ingredient you might have.
I think the site is only about 6 months old so there are only about 800+ books indexed. But, out of my 25 books that I inputted, only 3 weren't indexed (including my beloved Flexitarian Table). But, it looks like they are constantly adding more.
Here are the links to the site as well as to the Globe article.