A nice feature would allow users to pre-record an audio "intro clip" which would play before the call begins. The user would call into Ether, record the intro and assign it to a listing. Then, when a caller initiates a call, they would hear the regular Ether intro, followed by the user's "intro clip".

That way a computer consultant who allows customers to "start the call for free" could customize with info like, "Thanks for calling. Before we start, it would be helpful to get your computer booted up. This call will be free until we both agree to start the billing. Hold for a sec while we get connected..."

That's a fantastic idea!  I would really like it if we could have an intro like that.

Monica