http://www.columbusracing.com/forums/showthread.php?t=82211
http://img22.imageshack.us/img22/4317/gedc0388.jpg
All of the visible wires are in that black looming now that someone else mentioned. I'm sure there are other places to get around town or maybe cheaper online, but I got it at Micro Center. You can get a lot of different little connectors there too, like every 90 degree hdmi connector to help route the cables.
If you own a house run the wires through the walls and get wall plates from Micro Center or http://www.monoprice.com
For behind the a/v stuff, put everything in there 1 by 1 and run the wires. Wrap the wires up and hold them together with something. I use simple wire ties, like you get with trash bags or on bread bags. Very easy to use and reuse. Be methodic and slow with this process and it will help.
You can get some 'exact' length (by the foot) cables from these websites to help cut down on the wire clutter.
http://www.tartancable.com/
http://www.bluejeanscable.com/
Tartan is their less expensive but still very well made line. Owned in the USA, all HDMI cables terminated in the US and probably the only place that makes HDMI cables in the US. All but 1 of their HDMI cable lines is made in the US.