I have checked my e-mail on my Nook and while it's a workable program, but it does take some getting used to. You scan and scroll with the touch screen while reading on the one above. I'm sure the iPad functionality for web-access is much better.
To my mind the Nook is definitely a one function gadget, but I'm okay with that I bought it to be a one function gadget, kind of like I bought my iPod to be a one function gadget.
How is the nook for outside or in the dark?
For the nook, outside it is just like reading a regular book. If the light is dim then you will need more light, if it is super bright then you may have a little reflection/glare. As PP noted add a clip on light for @$10 and you can read a Nook in the dark.
I think the iPad is great - if you can afford it. With a desktop already, I couldn't justify the extra cost of the iPad. Believe me I thought about it - it had been announced when I bought my Nook.
I am a reader of paranormal romance and many more books are available from independent booksellers in e-book format than in printed which is why wanted one, figuring I'd stick to regular books for books available thru mainstream book sellers. To my surprise I've found I prefer it over a regular book. I've read about 200 books on my Nook (yeah, I read that much

). I love that I can switch books for one reason or another and then go back to a book and have it open to the page I left off on.
The only thing that I didn't do that I would recommend doing is buying the accidental damage coverage when you purchase. I've not yet damaged it, but I've had a couple of close calls where I fell asleep reading it and woke up with it hanging off the edge of the bed

. I did drop it once and my cover saved it (I have a leather cover from Oberon designs best money I ever spent!), but if the cover had been open it would have been toast.