Home theater cable organisation and childproofing

This is what it looks like behind my current TV unit. Does anyone have suggestions for techniques or products that would help make it tidier? I have a new unit arriving in a couple of weeks, which would be the perfect time to do it.

Cables include:

Two power boards, one has power all the time, one has power only when the TV's on

Three 12v power cables for the fans required to keep the Onkyo receiver / PS 3 cool

A switch to manually turn the TV/amp off when we don't need it. This is mostly because of the cooling fans.

5.1 Speaker cables - left, right, center, and sub are all in the same area

Various HDMI cables

Power cables for a router / WAP, Harmony charger, PS3 IR adapter, TV, PS3, R.Pi, phone charger, and who knows what else

Probably other things

I guess I'll need some kind of cable management system. I don't know if that's ducting, some way to fasten them to the back of the wooden entertainment unit, or what.

I think for childproofing I'm just going to make it physically impossible to access with one of those big child fences.

Any ideas appreciated.