When I was in Brussels with Jonathan I discovered Apple TV, a small black box which plugs into your HD TV and then talks to your computer. It allows you to listen to your i-tunes music and videos, watch Youtubes and Flickr photos and listen to internet radio. If your TV is connected to a surround system you can therefore enjoy Youtube clips and your music in higher quality in a different room on your TV.
Being a sucker for gadgets, I bought one for around £95. It works very well, though you have to have your i-tunes open to listen to your music collection.
It's a small box, easily connected if you have two hdmi ports on your TV. If you only have one, you'll have to buy a switch. (Amazon sell a Micro- 3 Hdmi switiching box for about £11.) Linking with your itunes account is fairly easy, but you must have the latest 10.1 version of i-tunes with "home sharing" activated.
It works well, especially if your broadband connection is reasonably fast.The natty little remote control allows you to navigate easily and search (somewhat ponderously) your Youtube videos. You cannot browse the internet.