Thanks for all the replies guys.
Paul - I would have loved the end result of doing that, but I wasn't up for the hassle I'm afraid and once they are in there then you've written off the cables if you ever move. Mounting the TV on the wall and painting it (the wall that is) was all the DIY I could summon the will to do!
Benny - I know what you mean, it's taken me a year and a half to do it. But (and I hope I'm not speaking too soon :O ) if you do it properly and use the right type of fixings for your wall then you will really be fine.
Edit - yes I've already got the trunking which can then be painted the same as the wall, that's a job for this weekend!