I've been advocating for Kindle with my authors, which can be read on all mobile devices... iPhones, Windows PCs, Macs, Blackberry, Android, and the iPad using free apps: http://tinyurl.com/readkindles
This commercial made me smile, "Buy once. Read everywhere."
Admittedly, as a graphic designer with a passion for unique book design, I do not like what happens to books when turned into eBook format and have struggled to make the transition. I am waiting eagerly for the ability to view the pages as they appear in print. While we've signed with Apple for iBooks, the conversions for my creative designs are proving difficult — for now, buy our Kindles!