Another great way to see what is exactly filling up your iPhone, and to get a general profile about your own device, is built right into the interface of the iPhone itself. Start by going to the iPhone Setting function.
Once there, go down to the third block of options and choose General, which hovers right above Mail, Contact, Calendars. The very top option of the top block will be About, which is right above Usage.
In About you are going to get a clear profile of your current iPhone. It will show how many songs, video, applications and photos you have. It will list your overall capacity and how much space you have available. It will give detail about your specific version, your current cell phone service carrier and the Serial Number and Model of your iPhone. More than this, it will give your Bluetooth, IMEI and ICCID numbers, though most users will not find this useful. At the bottom of the About section will be a Legal option, which gives you an overall list of legal notices for your iPhone.