whether it will get around their IP filtering or not for you Phil i don't know but it always got around my school then colleges IP filtering
go to your browsers Internet Options (I use Microsoft Internet Explorer)
Choose the connections tab, then click the LAN Settings
In there there should be a tick box and then some boxes for you to enter a proxy address and port, which you can constantly get new ones from:
Proxy IP List - Download Proxy List - USA Proxy List 3128
Personally i wouldn't tick the dont use proxy server for local settings though you'll have to turn the proxy off for accessing routers and internal sites like that but once done ok it all and try yell.com again and see where it leads you.
Like I said, i'm not sure it will be enough for yell but it might work...