I'm so stupid.
I've had my 19" CRT sitting unused on my floor for months and months. Finally, in a mad fit of brilliance, I finally hooked it up to my laptop. Combined resolution is 1280*1824. Makes up for my laptop being unable to go to 1600*1200.
Optimally, I'd put the CRT on something just behind my laptop so it really was right above my LCD so they were physically in the same location as they are desktopically. As it is, the CRT is physically to the left and desktopically below.
On the plus side, my desk hasn't been so clean for ages. The floor, on the other hand, has acquired a large collection of stuff that belongs on the desk. Or belonged until the CRT took the position of honour.
I have a couple more spare CRTs, but I'm out of ports and I don't know how well a Presario r4000 would support five monitors. Well, maybe I do know, and the outlook is not good.
Oh, and on the plus side, my room will be much warmer with a 19" CRT running in the corner.