I just got my new 3gs 16gb Iphone about 4 days ago. I come from a BlackBerry Curve. On my BB I have it set so that after a certain amount of time the phone locks up. The Iphone has this also but this is not the function I am talking about. I want to know if there is an app or some setting I cannot find that will allow me to instantly lock the screen? My BB has a button on the side that if I push it, it locks it. I don't wish to keep my lock screen time at instant so that isn't an option. I appreciate any help.