Behold the SIM that uses different networks!
Well, there's a company that are looking to end that, with a SIM card that automatically switches between a bunch of carriers. It is called the "Anywhere SIM" will alternate between Vodafone, O2 and EE's networks to try and get the best signal.
It'll also offer a single, flat rate if you're roaming across Europe. Sounds alright doesn't it? Well, naturally, the major mobile networks of the UK are opposed to this, because they stand to lose money with such forward thinking.
However, the startup that is developing this seems to have got around the problem by working with a company based outside the UK.
Basically, if you get one of these SIMs, it'll be like having a foreign SIM while in the UK. This firm say that they've already got roaming agreements with British carriers, but they might yet throw their toys out of the pram.
So what's the deal? Well, at launch, there'll only be a pay-as-you go option, while pay monthly plans will be ready to go in Autumn. It isn't cheap either, with texts costing 5p, and it being 5p per megabyte of data and 5p per minute for calls. And there's no 4G either. And the SIM won't switch mid-call.
All in all, it looks like a bit of a mess, but these might be the kind of problems that get ironed out if people pick up on it. We just don't know, but it looks like something to keep an eye on at least.