Would something like this work cross platform, say Ubuntu and Windows 98?
Yes, to a point:
You'd essentially have a network with two computers on it, and can do anything network related supported by the computers in question.
Two catches:
- under Ubuntu you'd need to be able to do SMB (Samba) network mounts in order to be able to connect to a share on a windows PC, which may need additional components to be installed / configured
- Under Windows 98, you can only connect to a network resource with the login credentials of the user that is currently logged on -- you can't specify an alternate username. Not really a problem, but you will need to make sure that that specific user/pass has access to the share on the host. (Under Windows NT/2000/XP/Vista you can authenticate with any credentials, but not under Windows 9x)