On my desk there are 3 computers, 3 monitors, router, wireless acces point, usb devices, network cables, phone line, speakers, wireless mouse.... No, it works fine here, all the cables are one big mess behind the table :lol:
At the "tv section" of my living room all the wires for CDTV, CD32, VHS video, DVD player, TV, amplifier, reciever, tape recorder, record player and digital TV reciever, again: all the wires are one big mess behind the TV, and still all of it works :lol:
And no, I don't use any expensive high-end cables and/or other equipment, except for my Amiga gear, everything was cheap.
The only thing that can interfer with any of it, is my mobil phone :-P