[CentOS] HP MicroServer

A bit OT, but I'm running CentOS-5.6 on this machine (in fact on two of them) and it seems to run perfectly - I've had no problems at all.

Except that I'd like to add a second ethernet port, and am not sure where one can find a card that will fit this machine. As far as I can see, it requires a half-height PCIe card, which seems to be rather a rare animal. (There doesn't seem to be a standard for the backplate.)

So I'm wondering if anyone has tried this? Incidentally, is there a forum anywhere for users of the MicroServer under Linux?

(The machine is unbelievably cheap at the moment, due to a bizarre cashback offer from HP.)