Announced on Monday at WWDC, the iPhone 3GS is the third handset launched by Apple in as many years. Whilst there was no change to the aesthetics of the last model, internally it's a whole new beast.

It's not just the new software, OS 3.0, which has changed - Apple has also upgraded it with a raft of new features. Of course, if you don't fancy forking out £184/$199 for an iPhone 3GS, you can always purchase the previous model which has been discounted to just £61/$99. Ryan Block, former Editor In Chief of Engadget and now founder of gdgt, thinks that the $99 model will be hugely popular.

"The iPhone 3GS is definitely a big step forward for Apple", he told T3, however he believes the $99 iPhone "will do more for market share as they're going to sell more $99 iPhones than they will $199 iPhone 3GS".

Claudine Beaumont, technology editor at the Telegraph, thinks that "the iPhone is clearly moving from a product to a platform, with the software update being more important than the launch of the new 3GS. With everything from tracking software to apps that can monitor your heart rate, it's hard to imagine a time when Apple won't have a place in every area of our lives".

T3 had the opportunity to get hands on with the iPhone 3GS at a product briefing on Monday in San Francisco, where we learned many a detail about next week's release. Check out the 10 things you didn't know about the iPhone 3GS below -

1.) Recording video

You can now record video, which is shot in a VGA 640 x 480 codec. It's shot at 30fps maximum, however that will decrease if you're shooting in low light.

2.) Editing video

Editing video footage shot on the iPhone 3GS is a breeze. However, it's worth noting that once you edit the video, the footage edited out is lost permanently, never to be found again. Make sure you're happy with your edited video, as there's no going back.

3.) Processor

Whilst Apple won't comment on the new processor included in the handset, only telling us "there are a number of hardware improvements", it's actually twice as fast as the previous model. You'll particularly notice this when switching between programs, and opening apps.

4.) Size

It's the exact same size as the previous model, but is actually a shade heavier, 2 grams to be exact. Apple wouldn't confirm why it was heavier, merely telling us it was a combination of the "new technologies" inside. The new processor and camera module might have something to do with it.

5.) Voice Control

Apple's new Voice Control function is extremely nifty, but did you know that it can recognise hundreds of requests? You don't have to be specific when asking 'what is playing now?', as it will also understand other phrases such as 'what is this?' 'name this band', and so on.

6.) Light sensitive

Whilst there's no flash, Apple has at least considered indoor snapping, improving the light sensitivity hugely on the iPhone 3GS. When we tested it in a darkened room, we noticed a dramatic increase in detail being picked out, not only in photos but the video as well.

7.) Green

No, it's not painted in spring green, we mean green as in environmentally green. Apple has used arsenic-free glass, a mercury-free LCD and the packaging is made from post-consumer recycled materials.

8.) Tethering

True, you can now connect an iPhone to your laptop - both Mac and PC - and use it as mobile broadband, but at what cost? In the US, the network AT&T doesn't currently offer tethering, but plans to introduce it in the coming months. It's expected to be fairly pricey, and unfortunately it looks to be the same here in the UK. Network O2 has remained the exclusive carrier, and with it comes steep tethering charges - an extra £14.68 a month for 3GB of data, or £29.36 for 10GB.

9.) Find My iPhone

Insurance doesn't come cheap, so it's a traumatic experience losing any phone, but particularly an iPhone. MobileMe customers can register for Find My iPhone, which as the name suggests, can help locate your phone if it gets lost or stolen. Log into MobileMe, and you can see on a map the exact location of your iPhone, and send a message to it saying it's been lost. Alternatively, you can ring your phone, and whether or not you left it in silent mode, a message will sound saying it's been lost. If your iPhone looks lost forever, you can remotely wipe all your data, and if it ever turns up, simply plug it into your computer and it will restore all the information.

10.) It can unlock cars

Not any old car, a ZipCar. ZipCar is a car rental company which has cars across the US and the UK. Download the app, and if you need to rent a car that day you can type in your post code, using the new embeddable Google Maps, it will display the ZipCars in your area which are free to hire. If you can't see the car on the street when you get there, you can tap a 'horn' button on your iPhone and the car horn will actually sound for you, alerting you to its location. Once you get there, you can then unlock the car remotely using your iPhone, and then find the car keys inside - and you're off!

Via T3