iPhone only: iPhone application iNap uses your location-aware iPhone to set off an alarm to alert you when you're nearing your destination. Say, for example, you're riding the train to work but want to catch some shuteye on the way. Just fire up iNap, set your stop as the destination, and let iNap worry about the rest. You can tweak the alert radius to make sure you're up in plenty of time, from 0.1 to 100 miles. iNap works with any iPhone, but the results will be most accurate with an iPhone 3G. Also, you'd definitely want to make sure you've got a signal near your destination; the app obviously won't work if it can't determine where you are. iNap costs $US1 from the iTunes App Store.