Dan, to answer your question, it definitely can be worth it in the right situation. Since silver speaker wire will obviously make for a "bright" sound, as compared to the "warmth" of copper(don't even need to listen, you can tell just by looking)it can make a huge night and day improvement with warm receivers such as Marantz, but would be a disaster with, for example, a Yamaha receiver, which the author should have pointed out.
Okay, back to reality; the article is of course pure drivel and the author apparently doesn't have a clue about audio technology. Silver has a slightly lower resistance than copper, as has been pointed out, but the difference is negligible; for example a 21' silver wire would have about the same resistance as a 20' copper wire of the same gauge. The main difference is that silver is about 80 times as expensive as copper and it makes no sense to use it instead of copper to simply act as a guiderail for the electromagnetic wave that carries the audio power/information to the speaker.
Another point where the author demonstrates his lack of knowledge is when he suggests that there's no problem in having the two conductors widely separated. Inductance in speaker wire is directly proportional to the distance between the centers of the two conductors and is no problem with the usual closely spaced lampcord. Leaving them inches apart would greatly increase the inductance, causing a loss of high frequencies. That sort of speaker wire might indeed sound "different".
