Oh goodee, re the 2 Wire
I read an article just recently that basically said that by using the third wire on a telephone nowadays is not really required with modern phones and can slow down a connection drastically.
Something to do with it going around in a loop, I did try to find the article, but alas could not find it again, somewhere on CA (I think).
The third pin/connection is the connection used to allow the ringer to work on extensions.
Kitz, sorry for going "Of-topic"