I assume beating into submission the people responsible for locking it down is not an option?
Tried a
.HTA (MS HTML Application)?
That limits you to IE, but if it works you will be able to easily turn off toolbars and stuff, and no reliance on browser install locations.
Of course, it's effectively an executable still, so any paranoid admin that knows what they're doing will block them from working, but there's a fair chance they haven't too.
EDITED: 4 Jan 2010 12:07 by BOUGHTONP