Of the things that I find really useful about my iPad is the ability to stick pdf's on it and read them wherever I might be. It doesn't matter about the style of the pdf, it just works and I haven't had any problems at all as far as I can recall. My iPad has a number of articles and short papers that are colourful and easy to both read and navigate on the nice bright screen. But it's not the most efficient reader, and an iPad is a complete waste of money if all you want to do is read stuff.
The Kindle, of which Anne as the Wi-Fi version with the keypad and I'm getting the non-keypad version for Christmas (yes, I know how lucky I am!), is just one of the alternative e-book readers out there. One of the things I like about the Kindle is the ability to email pdf documents to it. The problem is that the Kindle renders the pdf by page, which can make the typeface very small indeed.
For documents that I write, the solution is simple. All I have to do is to create a custom page size (90mm by 120mm) with 1mm margins and no headers or footers (they're not really needed). I then change the font size to 10 and email the pdf from the print menu of my Mac. Nice and simple, even if a bit time consuming.
Of course the big plus is that I can email this pdf to anyone who wants it, and they too can read it on their Kindle too if they have one. Perhaps there is already a neat and easy solution to generating readable pdfs for Kindle from applications. I know there is something that will convert a document into the correct format for Kindle, but I haven't explored that yet.
I wonder if some bright spark hasn't already, or maybe would like to write an app onto which you can drop a document and it will reformat it for you. Rather like the way Tofu puts a file into columns to make it easier to read.