Hi All
Yes the session theme is simply a css that can re-display the html. We exclusively use PIE mainly because we want to use the device as an "out of the box device" as much as possible. This helps with management etc.
The session theme means that two students using two different devices eg one on a desktop and one on a Pocket PC can look at the same content but be displayed in two different ways. The PDA theme using a different font and colour scheme to the desktop model. A student entering a course can either choose a link on the course to access the pda theme or the course can be constructed to determine what sort of device is connecting and then swap to the appropriate theme.
In the design of the course we have set the navigation to the right rather than the left which means the main content is always visible and limits scrolling. The block on the page re-sizes to fit in to the browser's window.
more discussion can be found at
http://moodle.org/mod/forum/discuss.php?d=27303Regards
John