A little off-topic, but I've gotten a couple of PMs asking about what the heck XLR cables are. The information is spread around the net but isn't too organized. The wikipedia article is located here: http://en.wikipedia.org/wiki/XLR_connector
Basically, XLR cables are most often used in the pro-audio world for long distance (>25 foot cable runs) because they minimize interference. They are often used for microphone cabling, speaker cabling, and equipment interconnects. The cables also tend to be very flexible allowing a tight turn radius vs. large gauge speaker wire which may be a bit stiffer.
A pic (female connector on the left and male connector on the right):
There are 3 pins in the XLR: a ground, a positive (or "hot") and the negative (or "return" or "cold"). Typically, they "lock" into position and allow a little more abuse than your standard copper speaker wire connector options (of which there are several).
There are 2 types of connectors: female and male. Just like everything else labels as such, male connectors have the pins and female connectors have the holes (now that certainly sounds dirty!).
Here's an example of male connectors:
At the bottom right, you'll see several of the 3 pin XLR connectors.
XLR connections and cables allow for balanced audio. Balanced audio is a method of interconnecting audio equipment using impedance-balanced lines (XLR). This type of connection is very important in sound recording and production because it allows for the use of long cables while reducing susceptibility to external noise. A further bonus is that it also eliminates the "ground loop hum" that plagues us...especially with subwoofers.
In our applications, it simply means that will get the lowest signal noise floor (ie: "cleanest") signal that we can when running over long runs....or if we are simply crazy and like to have things way over-engineered.
Hope this helps clear it up for a few people.