UPDATE: Check out our new article 14 best Android tablets in the world

Now that the Apple iPad has rekindled, or should that be sparked interest in, the tablet form factor, there's a host of new hardware waiting in the wings.

However, it's not a particular device that will prove to be the biggest threat to the iPad, it's the user interface that's being adopted by many of the forthcoming tablets, and that interface is Google's Android.

Why Android?

If you're wondering why Android is the key to a successful iPad rival, you only have to look back at Apple's previous game changing device, the iPhone.

When the iPhone launched it lacked many features that we would have expected from a high end phone, but that didn't stop it becoming a huge success and gaining unprecedented critical acclaim.

What made the iPhone so special was the user interface and it wasn't until Google launched its Android platform that viable alternatives to the iPhone started to appear.

OK, so it took a little while for truly excellent Android handsets to arrive, but today you're spoilt for choice, with devices like the HTC Legend and HTC Desire trumping the iPhone on many levels. Put simply, Android now provides a user experience that's every bit as good as Apple can muster.

HERO: Android came of age with the HTC Hero and the first genuine iPhone rival was born

It's also worth remembering that Android is now a mature platform, so it will be far easier for hardware manufacturers to bring polished devices to market in a timely fashion. This means that the iPad is unlikely to enjoy the significant head start that the iPhone got.

Google also seems to understand the cloud better than Apple, with Android devices designed to operate completely over the air, with no need for a traditional wired connection to a PC. And while Apple expects its customers to pay for its Mobile Me cloud service, anyone who uses Google for their email, calendar and contacts will have full access to those services via an Android device for free.

GOOGLE SYNC: If you use Google for your email, contacts and calendar, you'll be able to synchronise everything with an Android tablet so you're never out of touch. Oh, and it's free!

Android is also a far more open platform than anything Apple will ever bring to market. The iPad, like every other Apple device, needs to be connected to iTunes whenever you want to transfer anything to it. With an Android based tablet, by comparison, you can drag and drop files directly to the device, or even copy music/video/files directly from a memory card.

MORE SPACE:Unlike the iPad, you can expand the storage in an Android tablet by simply inserting a memory card

The one area where Apple has Android well and truly beaten is its App Store. Although Android's own Market is growing steadily, it simply can't compare to the volume and variety of apps available for the iPad and iPhone. That said, as more and more Android devices arrive, there will be more call for Android apps and consequently more developers producing them.