New to iPhone so please forgive the ignorance. If using Wi-Fi or 3G to access the internet, is the connection broken and browser closed when the menu (o) button pushed, ie. no more usage charges? Thanks.
When you hit the Home button (o), it closes the application you have open. The connection may remain open (not necessarily actively using data) as long as the iPhone does not go into sleep mode (screen off). Once it goes into sleep mode, the connection disconnects after 30 seconds or so.