For what it's worth, I'm currently running a triple-head setup at work on Ubuntu 10.04, using this card
. One head is native DVI; one is running through an active DP-to-DVI adapter (but passive should work too since this card has a DP++ port, I just happened to have an active adapter on hand); and one is VGA. 4800x1200 pixels of triple-head goodness.
This card is no speed demon, but I don't have much need for 3D acceleration at work so it gets the job done.
Though I haven't tried it, you ought to be able to run 2 analog + 1 DVI on this card by using a passive DVI-to-VGA adapter on the DVI port and a DP-to-DVI adapter on the DP port.
The only issue I've had is that the Catalyst 12.6 drivers don't seem to remember which monitor is which after a reboot. I've dealt with this by creating a script that is set to run on login:
xrandr --output DFP2 --auto --right-of DFP1 --output CRT2 --auto --right-of DFP2
Oh, and I wish there was a way to get GNOME to put the desktop icons on the middle one instead of the left one, but I can live with that...
(click the pic for a larger version)