A friend logged into his computer remotely from my desktop using "Connect to Server" in the Finder. For my convenience, I had marked "Add Password to Keychain" in the options panel. He, of course, did not see that that option was checked, because the keychain option is no longer listed in the main panel as it was in OS 9.
He and I were both surprised (and somewhat disconcerted!) to discover the next day that his password remained on my computer, and that I could log in to his computer freely!
Just a word of caution to those logging into their computers remotely--check that options panel before you connect!
[Editor's note: A great example of the system doing exactly what it was supposed to do, and yet the results were clearly not what the user wanted! Definitely double-check the options if you're using someone else's machine to get to your own!]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20020320235939574