See
http://www.tlc-direct.co.uk/Main_Ind...idy/index.html
http://www.standsunique.com/accessories.html
and
http://www.overclockers.co.uk/acatal..._sleeving.html
Buy a big length of square ducting & chuck a lot of cables in there - easier to cut a lot of 6" lengths of the covering and just plonk them on as needed rather than try to figure out where to cut the holes.
My study used to look like a CEGB substation - it's still full of crap, but at least the cables are out of sight and tidy.