How does one get small icons on the panel?

[Sean Murphy <murphy erim-int com>]

I've been looking at some screenshots of different themes at
http://gtk.themes.org and noticed something that I haven't been able to
figure out how to duplicate.  Some people seem to have two rows of
launchers on their panel, with the icons being about half the normal
size.  I really like this look since it allows someone to put twice as
many launchers on their panel and still have room for a tasklist, clock,

mini-commander, etc.

So how does one go about making this happen?  I've read the Gnome User's

Guide about configuring the panel, and can't find anything in there.
I've checked in the Control Center, I've left-middle-right clicked all
over the panel and can't find anything!  I'm using the October Gnome
release under RH 6.1.

Here's a link that shows what I'm talking about:
http://gtk.themes.org/php/pic.phtml?src=shots/939674160.jpg
The corner panel that this person has down in the lower left corner
shows it clearly.