It's not a phone, it's not a netbook and it's not really a Tablet PC. Apple's iPad is a whole new kind of gadget - and it's much more revolutionary than it looks.
Here are 10 ways it's changing the game.
1. It's got an Apple processor
Of all the ideas that have gone into the iPad, this one may turn out to be the biggest: Apple kit now packs Apple chips. That makes Apple like Microsoft and Intel combined, and could prove to be a major difference between Apple kit and hardware built by others with bog-standard off-the-shelf processors. It might not happen this year, but Apple silicon will end up powering the iPhone, too.
2. It does colour ebooks
E-ink displays are easier to read for long periods, but the iPad's eBooks can be in colour - and could include other media, such as video. The potential for bringing magazines and other publications into the 21st Century is enormous.
3. It's ridiculously easy to use
Don't underestimate the importance of simplicity. Even the best netbook is overly complicated for basic stuff such as email, photos and web browsing. The iPad makes them all as simple as opening your fridge - and it doesn't do things for the sake of doing them. No, it doesn't have a camera. Why on earth would you want to take photos with something the size of a large paperback book? It doesn't make phone calls because it's not a phone. It doesn't have hooves because it's not a horse.
4. It adapts
The iPad isn't a computer that expects you to adapt to it. It's a photo frame that becomes a newspaper that becomes Facebook that becomes a games console that becomes an ebook reader that becomes a photo frame again. It adapts to you.
5. It uses multitouch properly
No matter what Steve Ballmer or Steve Jobs says, using multitouch on a traditional computer is like strapping a jet engine to a pig: technically possible, interesting to look at and pretty much pointless. The iPad has been designed from the ground up as a multitouch device, and as a result its interface is based on what works rather than what everyone's been using for two decades.
6. The best bits aren't here yet
Where were the textbooks and the comic books and the enhanced ebooks, not to mention the so-amazing-you-can't-even-imagine-them killer apps? They're all coming. If Apple had been showing the iPad to all and sundry it wouldn't have stayed secret for very long. Now it's out, the developers can start building things for it.
7. Everybody's going to copy it
These days, every smartphone has an OS that looks very like the iPhone. You can bet that within weeks, we'll start seeing a whole bunch of media devices and tablet PCs that look very like the iPad.
8. It does apps
It's an obvious point, but it bears repeating: the App Store is a really, really, really big deal. Like the iPhone, the iPad's hardware doesn't have everything a geek might want - but it does have an excellent OS and a great big stack of Apps. That's what makes the iPhone a must-have, that's what's going to make the iPad really compelling.
9. It's really cheap - and could get cheaper still
That $499 price point is really, really low - and we can't think of any reason why media firms (newspaper publishers, perhaps?) couldn't offer heavily subsidised iPads as part of a subscription. They get paid, you get a cheap iPad, Apple gets another user, everybody's happy.
10. It's the first of a new breed
The first iPhone didn't do 3G, didn't do copy and paste, didn't have a compass, and didn't have an App Store. Look at it now. If this is what Apple's up to now, what on Earth does it have up its sleeve for version 2.0?
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Writer, broadcaster, musician and kitchen gadget obsessive Carrie Marshall (Twitter) has been writing about tech since 1998, contributing sage advice and odd opinions to all kinds of magazines and websites as well as writing more than a dozen books. Her memoir, Carrie Kills A Man, is on sale now. She is the singer in Glaswegian rock band HAVR.