Now, I am a Uni student so I'm not exactly the most financially-secure, money-making person and I know that, but there are LOADS of students who spend £30/£40 a month on their mobile phone contract. They all have the newest Blackberry/iPhone/HTC and with no part-time job/ only their overdraft to support them, I wonder "why?".
One of the life lessons you learn at University is how to properly budget money and to cut out unneeded expenditure. Well surely paying that much for a mobile phone is a tad ridiculous? Maybe it is like what the BBC article suggests which is that "the fear of "bill shock" was so great that customers typically bought four times more talk time than they used." I could see why this would be the reason people spent so much on their mobile phones, as they don't want to wake up to the shock that they accidentally left their internet turned on or forgot to hangup a call to a friend. However, I think that one of the best ones to save would be by switching phone contracts.
You may laugh, but I'm on the Tesco mobile network. Check this out: Tesco mobile. This is a list of sim-only tariffs. Yes, you don't have unlimited everything forever, but then why do you need that? You could pay £10 a month and get 500 mins and 5000 texts. Also, the Tesco network is a 50/50 joint venture with O2 so you will get decent phone coverage too.
So my thrifty tip is to make sure you are not paying an excessive amount for your phone contract when you could only be using a measly portion of it; and if you realise that you aren't as big a phone user as you thought you were...then want to join me on Tesco Mobile?