Most people will readily agree that mobile phone calls are still too expensive, especially those made to foreign destinations. It’s easy to believe that every minute of an international phone call currently funds a part of some distant politician’s luxury villa, which is probably only partly untrue.

Which is why it’s nice to see that some people are still fighting the good fight. The new BiBiTel SIM Skin product for instance is a rather innovative take on the whole cheap calls game, but instead of using calling cards, the company actually provides a stick on SIM which fits on top of your existing SIM card to deliver the savings.

The advantage of doing this is you can still keep using your existing card for domestic calls in and outward bound, and there’s no need to deal with fiddly access codes etc. The BiBiTel SIM just sits there waiting until it detects an international call from you, at which point it springs into action and routes it over the cheaper network. Clever.

The sticky SIM also realizes when you’ve gone roaming, and automatically switches into cheap call mode then as well, although in this case it automatically flips into callback mode when you make a call from abroad. Still it’s pretty convenient all round, and probably the next best thing to having a cool dual SIM phone. It works with 3G as well as standard GSM and there are apps for Apple, Android and Blackberry handsets.

You can switch the SIM off and on in a flash by dialing shortcodes (e.g. #99) and query call balances the same way. If you’re someone who regularly needs to call out of country, then this is definitely something you should explore. The call tariffs are seriously low priced, and the price of the SIM itself is just £19.99 which includes a tenner’s worth of credit.