As an e-Reader, there is no comparison. Price, screen, battery life, and I'm sure a bunch of other categories goes to the Kindle (and other similar devices). I consider getting one from time to time, but prefer physical books when reading.
The only nice thing about the iPad is its non
e-Reader capabilities. It's a decent tablet for browsing the web, doing basic tasks, and has a bunch of cool little apps. Personally I'd rather get a cheap laptop for that price, but I can see how it appeals to some.
I got an iPhone last year, and since then it's actually offloaded some of my browsing tasks from my PC. I can sit in the family room, pick the thing up, and quickly look up something on the web, check the weather, see who an actor is on IMDB, etc. Obviously for anything major, or even writing emails, I go to my PC.
Even if I didn't have an iPhone, I still wouldn't get an iPad.
"Space. It seems to go on and on forever. But then you get to the end and a gorilla starts throwing barrels at you."