There's also http://tvplayer.com/ if you want to watch live telly, and it's officially supported by the broadcasters involved and has no ads (other than the ads aired on the channels themselves), but neither TVPlayer or TV Catchup offer the on-demand parts of the respective channels. All three services, iPlayer/TVPlayer/TV Catchup work perfectly well in a desktop browser though, and I've just tested them all with success in the Metro version of IE too if that's your flavour.
Biting the hand that feeds IT
