I am currently 5 boxing eve online with Kavoom (-G) version in multicast mode (keys and mouse).

So 5 computers 5 screens.

Tricks:
I use full screen on all of them - all the same resolution.
Every UI is set up exactly the same. (set your snap to 12 or 24 pixels to make this easier)
I use 12 point font.
I fly all the same ships on all accounts.
Where possible, have all your skills the same to so that all systems respond at the same speed.

Be prepared to cry when you get hot dropped by a large fleet and lose all 5 ships :cursing:

Koto