There are MANY reasons to use an iPhone
It can be used as
a phone
a gameboard
a weather radio
a news channel
a web browser on a computer
an address book
an answering machine
a beeper
a dictionary
a photo album
a book (if you have Kindle)
a stereo
a record rack
an alarm clock
a notepad
etc etc etc etc etc etc
coaster?
I forgot... I use my iPhone as a video camera and a still camera.