Just my two cents on this issue, no flames please

Cat5 works great for telco lines.  Because it has more twists than telco wiring
it should provide more resistance to crosstalk.  Cat5 is 24 gauge wire, telco
is 22 gauge.  Both should be able to handle a 90volt ring, considering the small
amperage involved so I don't think the wire gauge here will make or break the
quality of phone call.  The big difference between the two kinds of wires is
the signal speed that you can run on the wire.  Cat5e can handle 350Mhz signals
while voice applications require no more than 400 kilohertz.  BIG difference
here.  Most telco guys recommend telco wiring for voice because it is WAY 
cheaper than cat5.  When you're deploying it by the mile like the telcos do, the
cost differential gets real big real fast.  If you're doing this for home use
I'd recommend what I did in my house:

48 port patch panel cat5e
4 cat5e jacks in each room

run all four pairs 568a (standard data wiring configuration) using solid wire

The benefits will allow you to run just about any kind of data in your home on
the same wiring without repunching down anything.  I use mine for ISDN, token
ring, ethernet and telephone.  If I had T1s I could use that too.  When voice
over ip equipment because a bit cheaper, I'll probably put one in my house
and get rid of my analog lines all together.  

	Mike Neuliep
	mike@illiana.net