On Win2K, if you have DHCP enabled, the option to add another IP to the same interface is disabled. Linux lets you have DHCP and static IPs on the same interface, not sure what Windows' problem is.

Yeah, that's only a problem in Win2k specifically. It bugs me, too. You can combine static and dynamic addressing on any other version of Windows, just not 2k. You can work around it on 2K with third party software, but the one I used for a while was a kludge to use and it didn't work that well. I'd like to see a "proper" work-around in 2k itself.