I've always wanted a service like this.

I needed a USB hub the other day, and I couldn't really wait days for it to show up from an internet store.

I could search the website of a big (expensive) chain store, PC World, but we have lots and lots of tiny local computer stores, and supermarkets with small tech sections, whose inventory is an absolute mystery unless I was to go and expend gas driving around them all. I often just bite the bullet and pay over the odds at PC World because I know they have the item, and I won't have to spend money and time travelling round and round.

I've often thought "where's my nearest store that sells X, right now?" would be a neat idea for a startup. It sounds like an administration nightmare, though.