Apple’s iPhone SDK is now available in beta format for free download (running your apps on a real iPhone is a one-time $99 charge).
The 2.1GB download contains the full Xcode 3.1 environment for Mac app development but also an extra 22MB of iPhone-specific SDK goodness including an iPhone simulator named Aspen Simulator (perhaps the code-name for iPhone). Whilst most of the iPhone’s apps are absent you can still access settings, photos, Safari and contacts.
Besides the cool idea of creating real iPhone apps you can also use Mobile Safari to test your sites on an iPhone – very cool! Here’s DamienG.com in the simulator when twisted round 90′.