I merely made a couple of basic Pouches for mine....
Mine is the Kindle 3 - the 'Keyboard' version, and I merely measured the Kindle itself, added a bit to allow for the 'walls',and added a bit more so that it wouldn't be too snug
First one (the one with the Coat-Of-Arms) I didn't allow for this properly,and thus is a tad snug, hence my doing a second one, I guess :-)
That said,I've also done a third one, merely because there was a design I liked that I wanted to do as a Kindle Pouch :-D
Anyway, here's my attempts:
http://kohn.livejournal.com/tag/kindle