Virgin Media's plans start at £6 per month -- offering 300 minutes, unlimited texts and 300MB of data -- and rise to £25 for 5000 minutes, unlimited texts and 20GB of data. All plans include free messaging options but also offer "data rollover," allowing customers to bolt unused downloads onto next month's allocation. It's basically combining perks from FreedomPop and O2 plans into one.

The company says that if people are intent on maximising their data allowance, subscribers can jump on up to 250,000 WiFi hotspots using its dedicated WiFi app. This, of course, also includes free access to 250 stations on the London Underground.

That might not stop some people blasting through their monthly allowance, so Virgin Media is making it easy for them to change their plans. Freestyle, which includes an extra monthly "loan" amount for handsets, and SIM-only plans both come with an option to move up or down each month depending on customers' data needs.

Also, if data usage creeps over with only a few days until the end of the month, Virgin Media says it will cap charges at £2 for each day, allowing users to download to their heart's content.