I’ve spent the past 3 days working behind the scenes for the NMC ;SL Pro! conference
We had a lot of challenges with voice chat on day 1, so I fiddled a bit to see what I could do to provide a live audio stream. The trick with Second Life is that the audio chat actually runs as a separate invisible application, so it is tricky to get both the sound from in world and the voice.
My solution was to use my PC as the source. I rigged my sound controls to use my headset mic for inout (when I needed to talk), but routing the sound out to the speakers, essentially mixing all the sound into one source. Rather than using the speakers, I connected the headphone jack form the speakers as a line in input to my MacBook Pro.
On the MacBookPro, I am running NiceCast for audio streaming (it sends the signal to our external hosted media stream service, the StreamGuys). In NiceCast, I could use its monitor volume controls to listen to the sound coming through, or mute it if I was talking (to avoid audio coming back into my mic).
Another plus for NiceCast is that it saves a copy as an archive, so I can post a record later.
It worked fairly well, at the limits of my small town ISP network provider. I called today, and they are running fiber up to my town, so I might have real internet soon.
Also, our staff uses Skype text chat as a back channel for dealing with behind the scenes support needs.