[agranig]

I've launched http://fonoso.com/ a couple of weeks ago, which takes your idea a step further and records full phone calls and could be used for podcast recordings over the phone, or any other use case where you want to archive and/or share a phone conversation.

I didn't put any time or efforts into polishing or marketing it, so if you (or anyone else) wants to team up, contact me at [e-mail]. Instead of twilio or something similar, I use my own SIP trunks to carriers, so for inbound calls, no fees are charged. It's easier to offer something for free with this approach :)