Just set this up on my 8gb 3g phone and blown away by how well it works..
Live tv (well about 1 min out from being live) on your iphone and the quality is amazing u get a choice fo the main terrestrial channels and some of the other freeview ones..
To set it up all u need to do is go on safari internet browser or google on your iphone and search for "TVcatchup iphone" once u get to that page just bookmark to your springboard and thats it then just click on it to start - it even works well just using 3g internet. - the picture quality is top notch!
channels available so far are:
BBC 1
BBC2
ITV
ITV2
Channel 4
Channel 5
BBC 3 (currently offline for some reason)
Film 4
E4
More 4
4 Music
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