Has there been any inexpensive item that enhanced your system's sound?


For me it was an inexpensive power cord that was laying around for years, a Pangea AC9.  I have it connected to my Yamaha A S2000.  I've tried the stock cord on the Yamaha and then some of my other cords, (Wireworld, VH Flavor 4, Acronlink/Oyaide custom cord and a MAC). I've had lots of amps and integrated amps over the years, and this is the first time the Pangea contributed to making better sound. It surprised me because I had tossed it aside and forgot about it.  Power cord performance is such a crap-shoot and dependent on so many other variables in the audio chain.  Any inexpensive item you've come across that enhanced your system's sound? 
foster_9
meerzistar, I also use the boos butcher blocks under several of my components and have used herbies tenderfeet underneath those..
Good mention on keeping switches clean. Even before crackles rear there ugly sound and become obvious some maintenance is a good idea. I bet they hinder sq even before the crackling starts, to a certain degree. Clean and lube is a good idea too, to shorten intervals.

Has anyone realized a sonic improvement with those line pillars, hmm? I apologize the correct term for them is not on file, but they keep your lines from touching ground by suspending them a couple inches off the floor. Few search attempts lead me back here http://www.amazon.com/Holdup-Contractor-Suspenders-Patented-No-slip%C2%AE/dp/B0060KRJG2

I can see different types of flooring holding a certain amount of moisture and being a good conductor of electricity. Even dry flooring holding charges of static electricity. And depending on seasonal changes. Just a thought.

It imagine it wouldn’t be difficult to fashion some up to avoid paying large chunks of money for them.

I might have to do some experimenting. A little guidance never hurts http://www.school-for-champions.com/science/static_materials.htm#.VzX9mdQrKLp

The question up top has me curious. Because I’ve witnessed first hand what different types of interference can do, subtle or seemingly non existent before hand.

Foster yes they are great. Now if I can only find a few more deeply discounted. They have countless applications. Unless you have a good surface planer in your garage the BOOS boards are a good way to go.