iPhone Data usage gone crazy?

Has your iPhone data usage gone crazy recently?  You have WiFi but you still have reached your FU limit?  It is likely that you have an app or two "stuck" downloading information and when you are out of WiFi range 3G kicks in and your data usage is depleted.

First thing to do is to switch off Mail

Settings>Mail, Contacts, Calendars>Select Your Mail Account>Mail>Turn to Off.

Next lets deal with Safari

Launch Safari, delete any and all pages listed, make sure you have nothing but a blank page. Then go to Settings>Safari>Clear History>Clear Cookies>Clear Cache.

Right now its time to reset the iPhone with a sleep and home button hold for about 20 seconds for a hard reset.

Once this is complete you can turn your Mail back on again and see if the data usage has returned to normal.

Thanks to Wjosten for this.