I haven't taken the time to note down the URL's but as I said above the most common one is a simple on-line Bingo website (which seems genuine) but the other one doesn't have a URL as its quite a sophisticated website which looks EXACTLY like a Windows XP standard Control Panel complete with icons for hard drive etc etc.

Only difference is that it has a "mock" antivirus scan running on it and a large announcement stating your PC is infected...it also has several pop-up windows asking you to "ok" or "cancel" requests for antivirus updates.

It it was just my PC at home then I'd say I'd picked up that virus that copies XP's built in antivirus (can't recall the name of it) but its happened on a work PC which is seriously locked down with firewalls and antivirus active scans galore so it's website related I believe.