on that note how many people use kindle for technical books how do you find them ?
I'll be honest, the Kindle format is pretty bad for most technical books. It's fine for anything that's pure text, but if you have a book with charts, tables, graphs, screenshots, etc., it really doesn't look as good as the book or PDF.
It seems that the publisher plays a pretty big role in how well the book transitions to the Kindle. There are some that are completely broken, like someone just copied-and-pasted from a PDF. There was one book where all the page footers were put into an appendix in the back of the book. Everytime the book referenced additional information in the footer, you had to dig through that appendix. I think I was going through The Shellcoders Handbook, and there was a page of shellcode where a few bytes were supposed to be in bold. Well, they weren't.
Others have clearly spent some time adjusting the book to work well in the Kindle format, and those are just fine. Unfortunately, it can be difficult to tell what you're going to get before you actually look at it. The best-case is when a publisher (i.e.
http://nostarch.com/malware) provides a package that contains a PDF along with the eBook formats. I'll load that up on my iPad and never look back.
However, the coolest thing is the syncing between devices. In addition to the Kindle itself, I have the Kindle app on my iPhone, iPad, multiple PCs, and the cloud reader for any PC that doesn't have the app installed. I can read a few pages while waiting in line someone on my iphone, and the next time I go to read that book anywhere else, I'll be prompted to skip ahead to my furthest location. Ironically, I rarely use my actual Kindle for Kindle books anyway.
I also travel frequently, so I love not having to carry heavy books around. I have 92 Kindle books, and I'd guess about 70% of those are IT/security-related. It's awesome to have your entire library in your pocket.