The SL voice chat facility is pretty good - better than Skype - but most of us feel a bit self-conscious using it. Here, you can only be heard by people on the same patch of land.
Use it how you like, though I'd prefer it if you don't have sex in my garden! I was thinking more about people who keep in touch with friends & family through SL. You can talk!! And, unlike a phone call, it's free
This is an experiment: there's only one private area at present. If it proves popular, I will extend it
Teleport: http://tinyurl.com/yu28zo