Netcraft: "What's that site running?" (top left of page).
Neat little tool I found via BinRev. Tells you what software a web server is using and has lots of other interesting links in there, IP addresses, addresses, server versions (!) and such.
Check it out, I could be wrong but it looks like NTL.com is using a vulnerable version of MS IIS (5.0). If so, it just goes to show what massive n00bs they are (and anyone that's had the pleasure of dealing with NTL customer services knows that allready).