pro tip: when trying to get help on the internets, try to use friendly language and give as much relevant information as possible.
multiple sessions on a single card? Sure. Only one session active at a time, though.Also I wonder if you can use Eyeinfinty with multiple x sessions?
multiple sessions on multiple cards, one session per card? *should* be possible, but I haven't tried. There's usually some non-driver restrictions (PCIe-ports, address space, ...) that make this kind of setup difficult. It's probably barely tested and if it breaks, noone really cares.
using fglrx of course, the OS drivers don't support eyefinity yet.