In the this is way overkill for a small home network I have been messing around with using a unused computer as a router-firewall-proxy. Today the final piece of the puzzle came into place.
I currently get internet from Qwest DSL, unfortunately because I am out on the edge of town and am not a priority it is only a 1.5 Mb line. It works but is not as speedy as I would like. For my configuration I have a 2wire dsl modem set in bridge mode. On my side of the DSL modem I have set up a HP/Compaq ProLiant DL360 that I got free from a fellow LUGer. It is running a copy of Karmic Ubuntu server edition. I configured it to connect to the DSL using PPPoE using ppoeconf. Finally on the lan side of the network NAT is provided by shorewall. I also configured the server to provide DHCP service and transparent proxying via Squid.
The final part of the local network came today via UPS, a D-Link DGS-2208 gigabit switch. So far, the move to gigabit Ethernet has been nice between my file server and desktop. To round out the network, G wireless is being provided by a WRT54G router with its routing features shut down.
All total it has been a nice little exercise in server configuration and network management. The next project will be configuration of an openvpn tunnel for remote system access. But that is a project for another day.