Super,
I don't know of any software like this -- but I will keep my eyes peeled since they are real nice apps. I speak from experience...
On my Sanyo PM 8200 there was a feature that acted as an answering machine... Here's how it worked:
While a call was coming in, there was an option called "call screening" that was available. When you clicked that option, it would answer the call, but it would be routed to a digital recorder within the phone -- a preset message that you record in the phone would play, then the person would leave a message while it recorded... You could even listen to it as they did it... Totally cool...
Based on the nature of the functionality, I don't see why a 3rd party app shouldn't be able to handle this...
I found
AUTOPILOT (for S60 smartphones - so, it won't work with "us".). But that goes to show you that it's out there.
Or not -- I just found
THIS article... possible hardware limitation - but I find that hard to swallow....
I'll let you know,
Thanks,
Matt!