If you look at the U.K. iPhone specs page you will see that dock adapters are not included in the package, but you can buy a 3 pack as an accessory.I just had a chat with someone on the apple store. I wanted to know how much the dock would cost. I think she was trying to tell me about the universal dock (with remote). But what she did say was that the iPhone 3G comes with a universal dock adapter (the plastic tray). So at least that's something, and that isn't mentioned anywhere.
If you look at the U.K. iPhone specs page you will see that dock adapters are not included in the package, but you can buy a 3 pack as an accessory.
http://www.apple.com/uk/iphone/specs.html
Perhaps she was misinformed then. She told me it would come with an adapter...