Thanks for your reply :-)
The other day I tried out a Kindle and I really like the way the (English) dictionary works. I've seen a link for using Eijiro on a Kindle (
http://www.ytsuboi.org/wp/archives/1387), but I haven't seen anything for going FROM Japanese (国語辞典、または和英辞典). Do you know of a dictionary that can start from Japanese words for the Kindle? If there were a decent way to make that work I'd go ahead and buy one.
Ｋｉｎｄｌｅの国語辞典や和英辞典が知りませんか？それがあれば、たぶん買います。
For anybody else who's looking for something similar to what I'm looking for, I recently found an iPhone app that sort of does it. If you purchase SkyBooks ($2) and Daijin ($22) you can read Japanese ebooks with a semi-integrated dictionary. SkyBooks can download books from Aozora (the Japanese equivalent of Project Guttenburg), and you can copy your own files onto it. (I've only tried it with plain text, but that's worked great.) The reader is nice, and you can select a word and immediately search for it in Daijirin, then when you are done you hit return and it reloads SkyBooks and returns you to where you were. It takes a few extra seconds of loading, but it is still a way to look up words with only a couple of taps. It's only Japanese --> Japanese (no English), but if you don't need the English then Daijirin is a great dictionary. The (Japanese) websites for the two apps are below:
http://sb.aill.org/
http://www.monokakido.jp/iphone/daijirin.html