I installed v6 on a local WinXP machine to check Drupal6 and start planning my site. Installation was easy, quick and smooth.
Then I enabled some of the included modules, in particular those related to language support, and then added the Hebrew language (which is written right to left).
I proceeded to create a regular user, logged in as that user and switched to Hebrew, leaving the default Garland theme. Indeed the language changed to Hebrew, texts aligned to the right and so did the logo.