I have been using Kindle 3g for some time now and I am frustrated (I got it as a gift, it was not my choice
While it can display non-ASCII characters (e.g. Greek, Polish, etc.) (it depends on the book, apparently some publishers do encode them wrong), I am unable to search text using them - there is no way to enter them on Kindle.
Also, Kindle search engine seems to be entirely based on full words. Unless I am completely wrong, there is no way to search for a phrase or part of the word which, for inflective languages (as Polish) makes the search pretty unusable.
Is there an ebook reader (I was thinking about Sony Touch Readers - touch screen would be also easier for text work/search/definitions/annotating etc.) which does have these capabilities (i.e. (1) real full text search (phrases, part of words, possibly wildcards) and (2) ability to enter international ('diacritic') characters into the search etc.)