I've recently been bitten by the analog telephony bug (again) and thought I'd have a go at creating a dial up Network Access Server (NAS). After some trials and tribulations and with the help of some great people online I've managed to get it working, and once again heard the glorious sounds of a dial up modem connecting to the internet... to quickly discover that bloated web pages make the experience even slower than I rememeber.
If you too are desperate to hear the screech of a dial up modem (and the drone of a Cisco router) you can build a setup for around £100
US Robotics Modem