Maybe some cable wrap or split loom would help.

http://cableorganizer.com/woven-wrap/

http://cableorganizer.com/wire-loom/colored.html

This is not an endorsement of or recommendation for that particular vendor. I've never used them. That's just what came up when I searched for "wire loom."

If you're looking for something to encase the wires going down a wall, you might try this:

http://tools.wiremold.com/diy/products/cordmate.asp

I've used that stuff to cover and route speaker wires.

Thanks for the recommendations- the third one may work!

You can also make a box that holds as many receptacles as needed with a cord to plug in and a switch to turn the lights on.

A metal box should be used, but you can the hide the metal under wood to make it less conspicuous.

Switches available include push buttons (some can control multiple lights with multiple pushes of the same button) or a separate button for each light and another to turn them all on at once.

You are pretty much limited only by your knowledge of how to wire them up and how much time & money you want to invest.

If you are talking about down a wall, bring them together then cover with a hallow molding, paint or stain same as the wall for a nice neat, clean look..
this is one dh did in our media room corner, if you can bring to a corner all the better..we have a cabinet below so they are not seen at all, he used cove molding here, glue in place.