That said, it's clear that there is power in the idea, nicely illustrated in an article in yesterday's Times, talking about a new service to fight identity theft using location services. The idea is simple and elegant: they monitor your credit card and your cell phone, and send an alert if there's a transaction that doesn't line up, on the theory that somebody might have stolen your card number.
It seems far from necessarily perfect -- for example, online transactions wouldn't work with this, since the "location" of the transaction is often far away. So I'd worry about false alarms. But it's still clever, and I suspect could be used to very good effect as an early warning of a stolen credit card. Indeed, the banks themselves might be smart to offer this service themselves, since they often wind up on the hook for fraudulent transactions.
Others? I know of Bump, which uses exact positioning to set up connections between two cell phones so you can do app-to-app transactions, but not much else. Are there other location-based services (aside, obviously, from Maps) that are more than just toys?