The Tiffen Smoothee, the Steadicam for iPhone's and Flip cameras, is still not available, though a recent email from Tiffen says that "The first Steadicam Smoothee unit will be available for the Apple 3Gs iPHONE camera very shortly. Really!"
The Smoothee will cost $199.95, which includes the Smoothee, Camera Mount Device, Carry Bag and Quick Start Guide. In January they will have the Smoothee for the iPhone4, new iTouch and Flip Mino. The mount is interchangeable, and according to Tiffen will be available separately for $24.95 (so you could use your iPhone and your Flip with the same Smoothee.)
You can sign up to be notified when it's available at this page: Tiffen: Reservation For Steadicam Smoothee