I rather stupidly bought one of these 3 or 4 months ago with my Kindle. I thought back then what a rip-off price was being asked for such a basic adaptor - £9 (Yes, NINE POUNDS!!)
As a functional product, it works perfectly: plug one end into a mains socket and the other on the supplied USB cable, which in turn is plugged into your Kindle and off you go.
But quite frankly I have made do with just connecting the Kindle to my laptop; or even using an existing mobile phone charger to the Kindle, with no ill-effects, and it charges perfectly well. And when you consider that one full charge will usually keep the Kindle going on its own for around a month, buying this glorified plug is false economy.
But what is even more appalling is the price of the adaptor now - January 2012 - a staggering THIRTEEN POUNDS!!!
This is the most blatant form of profiting I have witnessed by Amazon, and just goes to show what they think of their customers. I accept every company needs to mark-up its products in order to make some form of reasonable profit, but this is quite shocking!
So this review gets 2 stars, purely for the fact the adaptor does its job. But there are alternatives: you're not tied to buying this. Look around and safe yourself £13 and do it soon because I dare say in a couple of months Amazon might ramp up the price even more.