A friend of mine, a sometime Mudcatter, used to work for Monster Cable, a company that made its fortune by selling heavy-gauge, stranded speaker cables. I haven't asked my friend directly, but I think he's convinced that heavy-gauge wire doesn't really improve sound quality. Nonetheless, Monster has always produced (overpriced) cables of extremely high quality that would never break and never have a bad connection.

I've found that solid (not stranded) telephone wire works just as well for speakers. It's extremely durable and easy to connect. The main thing, is that you don't want wire that will break or get insulation damaged easily -and I've had those problems with the stranded stuff that used to be called "speaker wire." For ordinary speaker wire, I think the most important elements are durability and the ability to make neat connections. It really doesn't have to be anything fancy.

Same thing for ordinary telephone connections, but I've found that it's important to use higher-quality wire for DSL connections that carry a computer signal. CAT-5 and CAT-6 wires do make a difference, because the wires are twisted in a certain way to protect the quality of the signal. You can't trust a DSL signal to ordinary telephone cable.

-Joe-