EyeTV has a built-in web client, iirc. (That's actually reused by the iPhone app.) There is
documentation available.
It looks like live3g helps you get through firewalls, although you could do it without that by fiddling with your firewall. There look to be more details on how to manage your firewall linked from there as well.
Now... I haven't tried using it on the PC. And jmcgeejr says it doesn't work. I'm betting there is a way to make it work, though.