Everyone knows that the iPhone 3GS only comes in black or white varieties, but some unlucky users are claiming to have got their hands on a pink version. The thing is, these started out as bog standard white models but, according to some reports, they get so hot during extended use or when GPS applications are running that they start to glow pink!

The iPhone 3GS, which is currently totally sold out here in the UK, is twice as fast as the previous model. It is also twice as hot, too hot for some users to hold against their ear when making a call. Other users are complaining that when they run mapping software or any application that makes extensive use of the built-in GPS technology, the back of the device literally becomes too hot to handle.

So what is happening here? Apple itself is saying nothing, for now, but you can bet your bottom dollar that it is investigating the claims. Some are saying that it could be an iPhone 3.0 software problem, but that would seem very unlikely. Because not everyone with a new iPhone 3GS seems to have a hot pink model, and because there are also reports of the battery life being worse rather than better, as claimed, than the iPhone 3G there is some speculation that this could actually be a battery related problem.

Certainly there have been plenty of examples of overheating batteries causing problems with mobile technology in the last few years, including an iPod that apparently caught fire in some poor chap's trousers and 70,000 notebook batteries that got a little too hot.

It will be interesting to see what the official Apple line on this is, and how long it takes them to spin it out. If there is a battery problem it is likely to involve a large recall and a larger dose of humble pie eating from Apple.