To provide location-based services on Apple products, Apple and our partners and licensees may collect, use, and share precise location data, including the real-time geographic location of your Apple computer or device. This location data is collected anonymously in a form that does not personally identify you and is used by Apple and our partners and licensees to provide and improve location-based products and services. For example, we may share geographic location with application providers when you opt in to their location services.
See, not too evil. Besides, they touched on this at WWDC. But now that the policy is in effect (coinciding with the release of iOS 4), you should be sure to remember which applications want and need your location. You can change global settings in the new Location Services panel in General Settings, and each app should have its own setting as well. It’s not clear whether permission grants Apple &co. access to only your published GPS information (i.e. geotagged photos or tweets) or passive information like current location or frequently visited areas.
It’s likely that any GPS information you make public (published or passive) will be collected and shared or sold, so keep that in mind.
Be aware, though. If you turn off location tracking globally, you won’t be able to receive EXCLUSIVE OFFERS!!!