Not all cases fit both the iPhone 4 and iPhone 4S but here's some that do...

As pre-orders of the iPhone 4S begin today, we're concerned about protection for the handset as not many people seem to realise that not all iPhone 4 cases will fit the handset.  This is because the buttons on the side of the handset are of a slightly different size and position to the original iPhone 4.

Let's take a run through some of the best iPhone 4S case styles we'll be selling:

The Griffin Survivor case is one tough cookie - it's the most protective case Griffin have ever made bringing it up to the standards of the US and UK military.  

The iPhone 4S cover can withstand even the most extreme of conditions like wind, rain, dirt and shocks whilst your handset sits safely inside oblivious to what's going on around it.  Even better this case will also double up as an iPhone 4 cover, so you an test it out before you get your precious 4S.

Survivor is built on a shatter-resistant polycarbonate frame clad in rugged, shock absorbing silicone. A built-in screen protector stops your display being damaged, while hinged plugs seal up all your controls so that they are still accessible.  There's also a detachable heavy-duty clip so you can secure your iPhone to your belt or clothing.  All that matters is that whilst in this cover your iPhone is well and truly protected.

The second of our iPhone 4S cases to get excited about is the Case-Mate Barely There Case which protects your handset whilst keeping it looking stylish and thin.

Made from an impact resistant plastic shell, the Case-Mate Barely there is the perfect iPhone 4 case for those who want to protect their handset from day-to-day bumps and scratches, without taking away the style of the handset.  Plus it'll fit the iPhone 4S, so iPhone 4S users get the same protection and style!

This cover is perfect for those who like to frequently change their iPhone 4 accessories, as it's cheap and cheerful but excellent quality too.

Both cases are available now as part of the Mobile Fun iPhone 4S accessories range.