I'm only halfway through the posts that have been made since this morning, and already a few things are bothering me, so I'll list them before I forget...
1/ Someone (sorry, I forget who) labelled SGB as a 'swinger'. Swinging and polyamory are not necessarily the same thing. There are differences. Some swingers are poly, and some poly people are swingers. But it's not the same thing.
2/ Polyamory (although the etymology bothers me somewhat) means 'many loves'. It means that you're capable of loving more than one person at the same time. Deep, proper love. When I was in my non-monogamous relationship, my primary partner and I were deeply in love. I've been in love before that and it was the same. The difference is that the fact that 'love' does not equal 'ownership' is recognised in poly relationships.
3/ "Being monogamous (or, if your prefer, faithful)..."
'Faithful' and 'monogamous' are not synonyms. 'Faithful' is about respecting whatever boundaries are in place, being honest and honouring whatever commitment you have to each other. This is perfectly possible to achieve without being monogamous.
Anyway...
Back to reading the replies. This is a fascinating discussion :)