I do this with a third-party proxy. You can get a good free one from http://www.analogx.com , just look under network apps, it’s called simply " proxy " . It comes with an extensive readme on how to do it, but I can briefly explain it:
I’ll call your PC with the modem the " server " and the one who wants to share the " client " . Set the IP of the NIC in your server to 10.0.0.1 with a subnet mask of 255.255.255.0. You don’t need to fill in anything else in the TCP/IP config.
Set the IP of the client to 10.0.0.2, with the same subnet mask as the host.
The little proxy program runs on the server. You can bind it to your local IPs so people outside won’t try to break in using it. All you have to do after running the program is configure your email and browser on the client machine. In your browser prefs, choose to use a proxy server, and set it’s address as that of the server ( 10.0.0.1 , port 6588 if you use the analogx program). You’ll have to do the same thing for the smtp ( 10.0.0.1, port 25 ) and POP ( 10.0.0.1 port 110 ) server addresses in the email client. That little program will do email and SOCKS4 as well. And it’s free.