How hard would it me to create a locative lost and found service– like something that would associate a digital note about a lost object with a geocode, so that when you were in a place where someone had lost something, you'd see a note about it on your mobile device.

Why other kinds of notes could be improved by geolocating them? Craigslist missed connections come to mind, especially if a service could match them up with information about you and your whereabouts. So if you'd been in the corner Peets on Friday night, you'd see a missed connection tagged to that place and date. Whether you'd talked to the person behind you about Fellini's late version or not, only you would know.