My biggest gripe with user interfaces in general is that toolbars are
totally inflexible and not customizable to a <I>useable</I> extent.  The
panel, however, is very customizable and flexible.  Perhaps it could be
embedded within applications?  Then we could do all the things we want with
toolbars (panels)--add and remove applets or buttons (which perform menu
actions), add and remove as many toolbars (panels) as desired, collapse
toolbars (panels).