Another option...(this is what I do)
4 computers networked together (1 server, 2 clients, 1 gateway).
All have TCP/IP configured, w/ a default gateway set to the "1 gateway".
"1 Gateway" is a 486, running OS/2, and a Dial-On-Demand client.
If any machine trys to access the internet (ping, AIM, IE, etc..) then the "gateway" dials up my ISP, and connects the network. The dial-up client also provides a Network Address Translation-style firewall, for all outbound connections.
Works for me, and I'm sharing a 28.8 dial!! (Two people browsing at the same time is ugly!) but it means that two people can retrieve email at the same time, and I don't have to configure any dial-up adapters or accounts or passwords, except for on the gateway.