As with any other GNOME applet, you can use the middle mousebutton to easily move an applet around on the Panel.  Simply move your mouse over the , and then press and hold the middle mousebutton.  While holding the middle mousebutton, move your mouse.  You should also move the applet.  If the applet does not move, you will need to unlock the applet by releasing the middle mousebutton, and then using the right mousebutton to bring up applet options, as described in the next section.
Once you are satisfied with the applet's location on the Panel, release the middle mousebutton, and you're done!  You may optionally lock the applet to this location, as described in the next section.  Unfortunately, you cannot currently move an applet between Panels.
