Mystery Caller is off to Morocco for a two-week holiday. Sun, sea – and a lot of mobile phone use. He asks the operators what charges to anticipate on his prepay handset. How clued up were they and what did they offer?

Mystery Caller’s N8 contains his entire life. So it’s little surprise he is anxious about virus threats. He rang the operators to see what advice and software they could give him

Mystery Caller has scored big. His birthday landed him a bit of loot and he is off to the operators to see what handset he can buy outright. With up to £250 to burn, he expects big things from the CSAs this week

Mystery Caller decided it was time he took his ‘stalking’ habits to the next level. He wanted the best social networking phone out there for £30 a month

With Valentine’s Day drawing ever closer, Mystery Caller was out to impress his girlfriend. He is after a pink or purple smartphone on prepay and has £120 to spend

Mystery Caller needs a replacement camera for the one he lost over Christmas. What can he get that will give him the joys of a decent snapper as well as the ability to edit and upload photos for £25 a month?

Mystery Caller wants to start 2011 with a bang and went in search of a bargain just before Christmas that lets him carry his music library. £35 is the maximum he wants to pay per month with a free phone

Mystery Caller has a habit of getting lost. He is after a GPS enabled phone to use with his existing prepay SIM. With a budget of £60-£80 he set about seeing what the networks had to offer

Mystery Caller has just started his first year at university. Money is tight so he is looking for the best mobile broadband prepay plan out there. What did the big providers have to offer?

Mystery Caller is off to Australia but doesn’t want to take his expensive smartphone. He has a budget of £80. Could the networks offer a cheap but effective prepay option?