I would add that there are many exceptional power cords deserving of audition, and a number of them can enhance the listening experience on a par with major component upgrade.
I completely disagree with you Jade, that power cords are "a hoax and a pure waste of money". I think comments like that serve little purpose other than to troll for attention and polarize what was an even handed dialogue. Your qualifying comments aside, it's pretty clear you're making a concerted attempt to incite rancor or, well, I'll not hazard a guess.
My many trials and experiments have lead me to believe that a music system's power-lines and the type and pedigree of the power supplies in the components we use, provide the very foundation of realism in music reproduction. There are countless hobbyists who squander thousands of dollars on component upgrades with nary a backwards glance to their power-lines. Or worse, they simply buy whatever AC bandaid is popular at the moment, without taking the time to listen to a variety of AC alternatives.
No less attention should be paid power-line optimization than that paid to the choice of one's amplifiers, source and speakers.
Dedicated lines, high grade outlets and top quality, synergized power cord selection has done as much to improve my listening experience as anything else in the signal chain. I've spent a lot more money on speakers, different preamps etc that did more to change the "flavor" of music's presentation rather than improve resolution, or absolute sound quality.
As MegaSam said, all components, power cords, cables etc change, color, or shift the character and presentation of music and sound. The $100 question is, Jade, which of these groups of products, individual cords or components have the proper balance and resolving powers that draw us all the way in to the music listening experience? The answer is as different and individual as each of our sytsems and tastes in music.
The holy grail of audio is individual time spent in exploration and the encouragement of the same in others, some of whom only too readily visit these sites in search of quick answers, and IMO, there are too many willing to give them.
I think if any hobbyist curious about power cords put together an audition list that includes AC cords from Electraglide, NBS, FIM, BMI, Audio Magic, PowerSnakes and JPS they'll come away with a profound apprecation of the effect a power cord can have on the sonic of a music system...which is best? Depends on system, taste, music, environment..how many pages can I write for? You get the idea.
Nice post Mega, I was a little more put off by the self important tone than you were.