So I decided to waste some more money and splash out on some (cheap) wireless kit. Why? You may well ask as I only have (and thanks to the total inadequacy of BT and the cable providers, only can have) a 56k analog line at home.
The reason? So I can surf when Debbie is watching something I don't like on the TV, or do the shopping at Tesco without buggering off upstairs.
I ordered a Netgear WG511 card (rumoured to work under Linux) and their WG602 access point from dabs. Fingers crossed it'll all work.
It's a shame that only Apple make a Wireless Access Point with a built in modem, and that it costs a whopping 180! (Over twice as much as the Netgear). So I'll have to have the upstairs PC acting as a router (like I do on the Ethernet network at home).