Synergy

The Synergy docs recommend using the display manager to control the startup of Synergy. I'm not sure if this is the best way to do it but here it is. Xlogin starts Synergy so that it can be used at the login screen. Xstartup kills Synergy. And Xsessions restarts Synergy for your login session. In this example raven is the host name of my Synergy server. I'm using fixed IP address and a host file. BTW, put all this code at the very top of these files so you're sure that Synergy will start. You should just have to logout after you've edited the files to see if they're working.

/var/X11/xdm/Xlogin:

# The following lines configure synergy and allow the keyboard and mouse
# to be controlled over TCP/IP from another system running as a synergy
# server.  Change the hostname in the third line if the synergy server
# changes.  Synergy is started by the display manager through this file
# at system start.  When the user logs in this instance of synergy is
# killed through the Xstartup file.  Lastly a new session of syenergy
# is started for the user through the Xsession file.
/usr/nekoware/bin/synergyc
sleep 1
/usr/nekoware/bin/synergyc --daemon --restart raven

/var/X11/xdm/Xstartup:

# The following lines configure synergy and allow the keyboard and mouse
# to be controlled over TCP/IP from another system running as a synergy
# server.  Synergy is started by the display manager through the Xlogin
# file.  When the user logs in this instance of synergy is killed through
# this file.  Lastly a new session of syenergy is started for the user
# through the Xsession file.
/etc/killall synergyc
sleep 1

/var/X11/xdm/Xsession:

# The following lines configure synergy and allow the keyboard and mouse
# to be controlled over TCP/IP from another system running as a synergy
# server.  Synergy is started by the display manager through the Xlogin
# file.  When the user logs in this instance of synergy is killed through
# the Xstartup file.  Lastly a new session of syenergy is started for the
# user through this file.  Change the hostname in the third line if the
# synergy server changes.
/usr/nekoware/bin/synergyc
sleep 1
/usr/nekoware/bin/synergyc --daemon --restart raven

Using synergy on a Mac/PC will give you a great range of mouse/keyboard choices than you would normally have on IRIX. ATM, I'm using an USB mouse with a scroll wheel.