On Wed, 05 Jun 2013 07:23:58 +0100, Martin Brown wrote:

Why would you bother when it is now possible to run WiFi at that range
...

Provided there aren't a load of other neighbours all vying for the
rather restricted amount of WiFi channel space. In a
residential/urban area a WiFi survey would be wise before accepting
it as a solution. Survey done overa few days and at the times that
the link is likely to be used. Not just how many APs are there but
also the try to see what throughput you can get.

... and have decent throughput with no risk of lightning damage to kit?

If you want galvanic isolation I'd look at fibre. No problem of duct
sharing either. You can get pre-terminated cables (be careful with
thends, they are delicate and can pull of rather too easily) and I
don't think ethernet fibre adpaters are excessively expensive.

Mains and signal cables inside the same trunking is asking for trouble.

And technically illegal. The OP hasn't said if the run is aerial or
buried.

--
Cheers
Dave.