For me, this concept seems sort of at odds with the way I cook and grocery shop. I don't often find myself with a wide array of ingredients that I don't know what to do with, but I do find myself spending too much at the grocery store because I can't easily plan a week's worth of meals using some base set of ingredients. I would love a site that gave me 5 meals based around approximately the same ingredients, told me how much of each to buy, and provided information about how to store leftover ingredients and how long they will last. Of course, I know very little about cooking, so maybe I'm the one who's backwards... just my 2 cents.
I can see this idea applied to drink recipes, though. I often have 3 or 4 half-empty bottles of different types of liquor- it would be great to get a list of 10 different drinks I could make with friends. On second thought, $10 says there's already a Facebook App that does exactly that...