I just received a 'missing call' from some number which looked as a mobile phone number. The phone rang once and than stopped.
As I was awaiting call from my local carpet fitter, I rang back and then I was greeted by robotic lady:
"Thank you for calling Discreet Numbers, this number is currently not in service".
I was interested to find out who those 'discreet numbers' are and it turned out that this is premium phoneline. I haven't seen any charge on my mobile bill (yet) but people on MSE were charged a quid or so per minute.
Here is the number: 07040827668
According to ICSTIS, this number is owned by Global 1 Limited:
Company name: Global 1 Limited
Contact: Mr Peter Green
Phone number: 0845 022 9999
Email address: firstname.lastname@example.org
Discussion at http://forums.moneysavingexpert.com/showthread.html?t=391692