I received a Kindle for Christmas last year and from a practical point of view it is fabulous. I went away on holiday and that was all the reading material I needed to take with me. It lives in my handbag and I have read it in doctor's waiting rooms, railway stations, when trains are delayed and other odd moments when i have had unexpected waits.
The one problem I have, and I have yet to meet anyone that shares it. I find it very difficult to read a book on it that I havent first read in book form. The reason for this is that when I first read a book I read quite fast and tend to go forward and back in it, seeing what will happen, re-read what has happen. I do not do a first read in a linear fashion, which you have to do with any electronic book.
Once I have read it in paper once I really enjoy re-reading on Kindle, I read in much more detail and pick up hints and cues in the text that I missed when I read a book. One of the first books I downloaded was the full works of Jane Austen, all of whose novels I have read time without number over the years, yet when forced to read Kindle style, line by line, page by page I found all sorts of sentences and background comments that I must have read but never noticed before.