I found some DSL speed tips. They work. If you have DSL, you should read them and do the same.

I went from speeds all over the map to a fairly consistent 600 kbps just running a new CAT5 line for DSL. Replacing the cheap, flat, old-fashioned phone cord running from my modem to the phone jack and the other cheapie in my patch panel with UTP phone cords boosted me another 30-50 kbps. That extra boost varies, but it's something, and I'm glad to be consistently above 600 kbps now.

Finding UTP phone cords is a challenge. Supposedly Lowe's has them but I can't verify that. I had one that I wasn't using for some insane reason. I found another one at a garage sale, obviously from a DSL installation kit. I don't remember what I paid for it, only that it was a lot less than it's worth to me. Digging through boxes of random cables at garage sales can pay dividends.

The easiest way to get them is probably to make your own from scrap lengths of CAT5/5e/6 cable. Just crimp RJ11 modular plugs onto the ends instead of RJ45. Radio Shack sells a package of 10 plugs for $6. Overpriced, but convenient. There's always a Radio Shack nearby.

Belkin sells a special shielded twisted pair modem cable as an "Internet cable," for around $20. I'm sure it's a very good cable, but it's not worth 20 bucks.

When looking at a store, as a general rule, flat cables are always bad, but a round cable stands a chance of being good.

If you have a fairly new house, chances are your phone wiring is pretty good, in which case the most important thing is getting a good phone cord. If you have a house built in the '60s like me, with phone wire run after the fact by a weekend handyman who either didn't know or didn't care how to avoid interference on the wires, that's another story. If there's 30 feet of bad wire between the telco and the modem, the quality of that last 6 feet of wire doesn't make much difference.

While you're at it, you might as well replace all your phone cords with these higher-quality models. Your voice calls will be clearer, and it eliminates the possibility of those cables introducing interference into the line. That interference shouldn't reach the modem, but "shouldn't" is no guarantee.