IP aliasing

Hi, 

Does anyone know how to add an alias to a
network interface? for example, get 'eth0' to 
respond to more than 1 IP address? do
I need to compile this option into the 
kernel?

I assume the system would reflect this as
eth0:1, eth0:2 etc for as many aliases that
you have on the same physical card.

If I reboot the machine, will the system keep these aliases?

Lastly, in a machine with multiple network cards, how does the system handle the 'ordering' of the network card names, such as
'eth0' 'eth1' etc? does it select this name according to which PCI slot you use, or 
according to whichever card was added first, 
irrespective of the PCI slot?

Jason