I'm very close to buying one - I love the idea of so many out of copyright books being available free of charge - even some which as far as I know are out of print & which I've wanted to read for a long while (like John Leland's Itinerary - free on the Open Library site
http://openlibrary.org/ ). Plus, you can download the free Calibre
http://calibre-ebook.com/ program, which will let you organise & most importantly convert any ebook file type (including pdf's) into the .mobi type that the Kindle reads.
Also, you can get this dead cool 'Tolkienesque' cover for it from Amazon
http://www.amazon.co.uk/gp/product/B...pf_rd_i=468294
However, a couple of negatives - first, according to the Kindle agreement on the Amazon site you don't actually 'own' the Kindle books you buy - you just purchase a licence to read them on the device. Which means they can be deleted whenever Amazon decide, that you can't sell them on or give them away (as you can with a real book), & finally reading the one star reviews it seems that some people are having major problems with the screen packing up, the thing re-starting or freezing & having to be replaced - one guy on his fourth replacement. Looking into it, the problem seems to be to do with the cheaper Amazon own brand case (the one without the built in light). Oh, & it seems that the Kindle software allows Amazon to read the whole contents of your Kindle every time you connect to the network - so watch what you put on there
There - all that with only one slight Tolkien reference to avoid being completely off topic!
I may take the leap soon - & I may put some Tolkien on there to try the experience, but I still can't help feel that out of all the books out there Tolkien's may be least 'right' for the format...