I know element case has a case sort of like what you are describing but it is for the iPhone 3G/3GS. It is called the liquid. http://elementcase.com/stockliquid.html
I am not sure about one like that for the iPhone 4.
Thanks everyone but the one in the youtube movie is the right one. What is it called? I see he has it for 3g/3gs/2g I dont know but I really want it for iPhone 4 and im 100% sure the guy in the store had it for an iPhone 4 (I saw him using FaceTime)...