Suggestions for a Strange Project?

[Mega Hurts]

One computer has never been enough for me.
Even back in the olden days of Z80 S-100 machines
(pre IBM PCs), I used TurboDOS with multiple SBCs,
and a strange multiple MicroAngelo graphics setup
of my own design.

Some things never change.

My current setup consists of four machines, running
Win98.  I use a single monitor and infrared keyboard/
mouse, and switch from one machine to another with
a KVM switch.  I connect to the internet on the first
machine, which runs a proxy, and the other machines
can run mail, FTP, news and web clients.  I use a couple
of the boxes for compute-intensive MPEG recording, and
when they are busy, can switch to the others for office
activities.  Soon I will change the fourth box to Linux.

To switch from box to box, I press CTL-CTL-1, or
CTL-CTL-2, etc.  The fun begins:

[1] I use background colors and a labeled icon to remind
me which context I'm in.  Things get fun when I am
working in a file, copy text or a graphic, switch to
another machine- AND FORGET THAT I CAN'T PASTE.

[2] Or I'm using my beloved and vital graphics pad and
switch machines, only to be reminded that the cursor
on one machine and one only is under Wacom control.

[3] All the clocks lose and gain time at different
rates.  This becomes important when recording off-air
scheduled events, and updating the clocks on four machines
is just another chore.

Well, Rochester... I'm thinking.  All these boxes can
talk to each other via that zippy 100Mb LAN.

Now, why can't machine #1 share its web-updated clock
info, and machine #2 share its graphics-tablet cursor
info when needed, and all of them write to a common
'clipboard'?

A lightweight task running on all machines should provide
the connectivity and clock awareness, cursor and mouse-key-awareness.  Any
suggestions on where to start?

Thanks