Quite some time ago, Amazon launched their Kindle ebook thingy. This looked to be quite a nice thing, apart from the little detail of it only being available in North America, depending on specific phone networks to function, and being pretty much tied to the US amazon.com store.
A bit later, they managed to sort out the networks thingy, and allowed customers in the UK to buy the then latest model. This was better, but it was still tied to the US store, which meant that if you wanted to buy books, you needed to convert all the prices into your local currency to work out if they were reasonable. And there was the problem that with it being a US store, some books you might have wanted to buy electronically were simply not available.
While all this was going on, I had my Sony Reader, a device whose usefulness is still limited by the frankly stupid prices being charged by Waterstones for current books. Hint: if you’re charging more for the eBook than Amazon’s price for the paperback, I’m not going to be giving you the money. You’d think that was obvious enough, but not to Waterstones, apparently…
Moving along, the Sony Reader is mostly neglected, and I (as I might have hinted) succumbed to the Oooh Shiny! and bought an iPad. I went for the basic 16GB WiFi only model, which works quite nicely for web browsing, email, Sudoku and, would you believe it, reading books. The Apple iBooks thingy is not too bad, but once again it’s tied to a store that has slightly odd pricing and (last time I looked) a limited range. But for things like electronic versions of O’Reilly computer books, downloaded in PDF format, the excellent Good Reader application is great. It’s a lot easier to prop up the iPad next to the computer when I’m working through something than trying to juggle a very large and thick paperback. Works well.
But there’s more – the thing about Amazon is, that despite them bringing out newer and better Kindle hardware, they don’t really care about the hardware. What they want is to sell books. They pretty much want to sell every book that gets bought, which is why they make a Kindle app for Windows, Mac OS and the iPad (amongst other things, more to follow, more than likely). Install the app, connect it to your Amazon account and you can browse the site and buy books, which are delivered immediately. This actually beats an actual Kindle, where web browsing is not as shiny, fully coloured or nifty as it is on the iPad.
But it was still tied to the US store, which was a bit naff. However, all that has changed. You can now order a new model Kindle direct from amazon.co.uk (pre-release stocks are all allocated, if you order now, you won’t see your new toy before 8 September), and more importantly, the UK Kindle store is open for business.
And it looks like it’ll do some quite serious business. Loads of books (over 400,000 right now, and that will grow), and generally priced below Amazon’s paperback prices. For instance, currently popular top-selling novels are below £3 each, which combined with the whole immediate free delivery thing finally makes eBooks look like a cost-effective option. And this is, in general, a Good Thing. 
So, if you have an iPad already, just get the Kindle app from the App Store and have a look at what you can get. For books with pictures, diagrams or other such things, the iPad app or a computer will be the best option. You lose the ultra crispness and enormous battery life you’ll get with the Kindle and its eInk display, but you’ll see more stuff. If you want to read books that are wholly or mostly plain text, then an actual Kindle is seriously worth thinking about.
There are two models on offer: the expected one with 3G and WiFi for £149, which will download books from most parts of the world with a mobile signal, at no additional cost, and a WiFi only version at a quite surprisingly low £109, which is cheaper than a Sony, and comes with a keyboard for annotation and the like. If you only want to download books at home, or where you can connect to a WiFi network, or indeed have one of those quite spiffy 3 MiFi dongles you can go for the cheaper model quite happily.
In fact, if I was making a recommendation, I’d say buy the WiFi model and a MiFi, which will let you connect your other toys to the internet when you’re travelling or just generally out and about.
See the Kindle Store for all the stuff. If you’re using AdBlock, you probably won’t see the picture links above, but the text one should work.
Oh, and one reason to consider the Kindle rather than using the app on the device of your choice: newspaper subs can only be delivered to actual Kindles for reasons that weren’t specified when I tried to get a sample. If that’s relevant to you, you’ll be wanting a Kindle.
 Waves hand vaguely
 eBooks lack the features of “pass on to a friend” and “donate to a charity shop” that physical books have, but also lack the “taking up too much space” and “where did I put that one, it should be on this shelf” features. Overall, so long as the prices are right, that balances out for me.
 The newer model, quite apart from looking cooler and being able to keep an informative display on all the time, also works properly with Macs, and doesn’t require juggling three buttons to make it work. Nice. I’ll probably upgrade mine at some point.