Linux and Public Access Computing?

An Anonymous Coward asks: "The Seattle Community Technology Alliance is a non profit, federally funded, public/private project that supports community technology centers in the Seattle area. We are interested in moving our public workstations from Win 2000 to Linux. In order to do this, we need good multi-lingual options and the abiltiy to create 'guest accounts' that prevent users from changing settings (to provide a consistent environment for users). What are the best tools for multi-user Linux labs? Should we use KDE? Gnome? How do we keep users from changing settings? We are eager to start experimenting, but would appreciate expert advice on starting points!"