That's a rather presumtuous presumtion Apple! I could have phrased that phrase better. I could be using Stanza instead, an application that's also free and is far more customisable. It lets me adjust the margins!
When I have more time I'll be doing my review of reading eBooks on the iPhone 4's screen… so far its been amazing. But iBooks isn't so crash hot. Maybe I'm just bitter that they stole the name from the iBook line of notebooks of which I'm a proud owner. That little 12" iBook G3 go me through high school, and was a great conversation starter for a shy nerdy dweeb ;).