If you or your library own, or are considering buying, an ebook reader, you should take a look at this great article from Gizmodo about ebook formats, DRM, e-readers and a lot of the factors that affect how those things interact.
The idea of an open ebook format that works on any reader sounds nice. Buy it from any source, read it on any device. In a few cases, it's true, and that open format thing can work for you. But, in reality, right now? You're pretty much going to be stuck reading books you buy for one device or ecosystem in that same little puddle, thanks to DRM. And well, Amazon.
I've been following the e-reader wars with half an eye for a while now, and I learned some new stuff.
Giz Explains: How You're Gonna Get Screwed By Ebook Formats (thanks, Michael Sauers, for tweeting this)