If enabled from the admin menu you will see a link to user preferences in the main menu, the user preferences page is a page for registered users (users with a valid login and password already logged in the system) where they can set up several preferences about the site and where they can see some stats and quick links to pages, blogs or galleries they have created.
The user preferences will display a screen such as the one presented, as you can see it has a box where the user can change his email, the theme, his real name, home page and it has a link to the user personal wiki page as well as a link to edit the page.
This screen can be used to set up different themes for users, in the future we plan to add a lot of themes, specially themes for users needing special accesibility features such as aural properties, bigger than normal text, abscense of colors, etc.
Basically all the preferences that can be set at the user level can be found in this screen. The user can choose an avatar for him, the pcik user avatar link can be used to let the user select hist avatar.
In this screen the user can also configure the user messages settings, the user tasks settings and what will be displayed in the mytiki screen.
This page is for the latest released stable version or release candidate(not stuff in CVS).