On a scale of 1-10, organizing cables and cords behind an entertainment center ranks about a .001 on my scale. But when it's all done and finished, the results are often night and day, not only just improving the aesthetics in and around the home entertainment center, but also possibly making your home a little bit safer thanks to better organized power and wiring. Here's a glowing example of such a project, from Kim and Scott of Yellow Brick Home, 2012 Small Cool entrants...

Scott geeked out on matching HDMIs to optical audios or something (while I refused to watch), whereas I had the ultimate excuse to make cutesy labels on our P-Touch. As much as I'm allergic to cables is how much I loove my P-Touch. Here's our view of the top secret through-spot (carved out of the bottom middle), which will ultimately be covered by records."
Even their dog seems perplexed how they got all those cords and cables so well organized (3 hours later). If your setup is a spaghetti monster of cables and cords, using a label maker can be a very useful investment for cable labeling. Or just use some bread tags.

See the complete project over at Yellow Brick Home and be inspired to get organizing this weekend (I am!).
(Images: Yellow Brick Home)

White Enamel Flatwa...
Cute one of the pup.
Cables look good. :)
I like the media wall. Nice.
I wouldn't use zip ties because you can't reuse them when you decide to change a layout. Also, when you must rearrange, I always feel like I'm going to slice myself trying to cut the zip tie. Big twisty ties are the best. :)
Actually, you can reuse zip ties.
http://lifehacker.com/5903220/unhook-and-reuse-plastic-zip-ties-with-a-simple-trick
They do make color coded velcro straps you can use for this purpose.
I've done this myself but didn't have the space you had to "hide" the mess. I like the color coded velcro strip idea!
Actually you can re-use zip ties; you just need a something thin like one side of a thin pair of tweezers or one blade of a pair of nail scissors to slip between the locking bit and the ridges and you can slide them undone, then re-use them.
But, given that they are usually extremely cheap for a pack of 50 or more, it's a little wasteful but not expensive to use them.
Twisty ties are great though. I use them too. :)