2 videocards in PC to use 3 monitors possible?

Hi,

I've searched Google but can't find a clear answer.
Is it possible to put 2 different video cards into a PC in order to hook up 3 monitors?

Motherboard: ASUS P8P67-M
Slots:
1 x PCIe 2.0 x16 (blue)
1 x PCIe 2.0 x16 (x4 mode, black) >>>>>> USED by current video card
1 x PCIe 2.0 x1
1 x PCIe x1
others are empty.

If possible, are they things i should be aware of when buying the second card? The current card is not a fancy one, the seconds doesn't need to be either, they screens won't be used for gaming.

Thanks