Can pointing device be manually loaded?

[Vaughn Treude]

Hello all again:
This is another question relating to my Sony Vaio running Red Hat 7.1, but 
it's not really specific to that system.  When I'm traveling, I use the track 
pad or a USB trackball.  At home, when I hook it up to my KVM switch (so I 
can use my preferred setup) I use the serial port for the pointing device 
(for rather complicated reasons I don't want to go into here.)  The problem 
is, when I change setups, Kudzu sometimes has trouble recognizing the change. 
 And I hate to have to reboot the system just because I've stuck the USB 
trackball on.  So, the question is: is there a way to manually force Gnome to 
change the pointing device, perhaps with some sort of command-line script?  I 
suppose I could have three versions of XF86Config-4, and restart X each time, 
but I was hoping for something a little easier...

Thanks,
Vaughn