If you are concerned you could run FTP (as in foiled twisted-pair).
It doesn't need to be a more full on type of STP where each of the 4 pairs has its own shield.
In this respect it would be roughly similar to how with coaxial cable induced currents tend to stay on the outer conductor.
You could ground the foil (it should have a drain wire when you strip it) because if running outside you can literally drive a metal rod into the ground and make a good connection to it, but perhaps grounding to an existing water pipe is easier.
As I understand it, would be safer if the foil part doesn't protrude into the sockets at either end to avoid unintended contact.
However, unless your outdoor cable was running to some kind of antenna or something else more likely to to be hit, or is likely to pick up noise along the run, it's probably not necessary to shield it.
Common advise is not to follow electrical (power) cables, but other than that it is the way the pairs are twisted inside ethernet (and good telephone) cables that helps to reduce interference.
prompt $P - Invalid drive specification - Abort, Retry, Fail? $G
prlzx on n e w n e t: ADSL2+ / 21CN at 2.5Mbps / 800k
Edited by prlzx (Thu 08-Mar-12 01:22:43)