This article from Tedium on the history of ebooks is really interesting. I was philosophically horrified by the whole idea of them until I used a Kindle (the original one) so it was interesting to see what came before and what’s changed over the years.
That said, I’m still somewhat horrified by them (while using my Kindle extensively) – not because of the reading experience or the technology itself, but by the business model behind it, which forces readers into “purchasing” DRM-protected content.
Breaking the DRM on your ebooks is illegal, of course, but it’s also an ethical activity if you’re doing it simply to retain the your rights to use the material in them without violating copyrights. In my opinion.