I use a combination of methods: in-wall conduit, stick on conduit, careful arranging of cables behind concealing structures. The only place I'm a little messy is in my equipment room which is itself hidden. Though when I do an equipment upgrade later this year I'm going to try to neaten everything up there.

ryan: do please give all of us with the horrible mess a hand in devising solutions for the cord octopus. Nothing so far has worked quite right for me

Nice cabling is not ugly. Get nice colors. My stereo rack has a shelf fo CDs as well; the space behind that is for the power rail and power cables.

I've used the hose from a canister vacuum to hide cables as well.

I have looked long and hard and never able to find the desk with wire storage I wanted, so I finally built this with some IKEA clearance white laminated top which I think it's either a table top or closet door. I paid $15 for the top.

The wire hiding part is made of poplar from home depot. Total cost for the real wood portion is only $30. I have some aluminum IKEA legs for $60

http://www.ikea.com/ca/en/catalog/products/10115519

Current table looks like this....

http://www.flickr.com/photos/yauser/3043081792/

I will finish it by trimming the sides with poplar as well.

Not sure what stain I will use if at all.