There is a lot of material available outside of Amazon, and you can download the books you obtain from any of the source, including Amazon, to a PC, swapping them to and from the device as you choose. If you turn the WiFi in the Kindle off, not only does the battery last for weeks without recharging, but the Kindle is detached from their system. The eBook wars that are now being fought out among Amazon, B&N and Borders over competitive formats has lead Amazon to now permit "lending" of books among Kindle owners. I am not sure how that will work out over time -- I do not buy many books from Amazon (or other vendors); there is enough free stuff out there, and enough innovative writing that is priced way "under market."
The price of Kindle has dropped to $139 for the base model -- which is about the sam as a half-dozen hardbacks from BJs or Costco. If you need textbooks or reference non-fiction, by all means invest in the forest; for most purposes, though, photons are one hell of a lot cheaper.
And Mrs bunneh really wanted one till the whole "you own the book as long as we say so" thing came up. Then nah. She just does the good old fashioned paper thing.
Yeah...I'm a furry...Deal with it!