Kindle doesn't quite have Stanza's functionality - you can't change the typeface and you can't dim the screen.

However, with Stanza it's only easy to read books in the public domain, such as old classics. I tried buying several copyrighted books online, only to be told that an online version of each book wasn't available in my territory. Very irritating.

The Kindle app seems to have solved that. So far I bought a couple of books off the amazon site without any problem. Kudos to amazon and not to ereader.com/fictionwise etc. for sorting out international rights issues for the books in their respective stores.

In summary, Stanza is better if you only want to read classics (for free). Kindleapp better if you don't have a USA credit card and want to read contemporary books, or if you have the Kindle hardware.