Jeff has an iPhone 4 and wants to know if there's an app that will map his travels through his GPS. Leo says that Glympse is a great app that does that if he wants people to know when he's going to arrive. Google does it natively at Google.com/dashboard under Location History, but he'd have to enable it in Google Maps.
Leo says that Apple has stopped this practice, though. It was mostly used to improve their location data for Wi-Fi. But there was an outcry over it, and they no longer do it. The iPhone also has location based advertising and reminders.