You can have several applications open at the same time. To switch between active applications, press and hold the home key, scroll to an application, and press the scroll key. To close the selected application, press the backspace key.
When you have an active phone call and want to check your calendar, press the home key to access the menu, and open the Calendar application. The phone call remains active in the background.
When you are writing a message and want to check a web site, press the home key to access the menu, and open the Web application. Select a bookmark or enter the web address manually, and select Go to. To return to your message, press and hold the home key, scroll to the message and press the scroll key.