Call centers are really boring and drive most people crazy. This project uses the twilio voip services api to deliver a dynamic playlist and mp3 to the person on hold. Songs are played through any mobile phone. The audio is retrieved in mp3 format from 7digital, converted to a phone playable encoding, and played to the waiting customer. After each song plays the caller can rate the song and echonest will find the next song based on the vote. When an agent becomes available the call can be forwarded.
A key feature is that the application stores the echonest session key along with the phone number of the person calling so that returning customers can pick up where they left off. If all call centers implemented this you would have a nicer "On Hold" experience everytime you needed some service.
http://waitingroom.consultfor.us
Ruby on Rails
The Echo Nest API for playlist
7 Digital for mp3's
Twilio for VOIP
My Brain