ESPN PlayByPlay is a potentially interesting product geared for turning young kids into sports announcers. It includes signature ESPN sounds, stadium chants, an 'on-air' light, 3 microphone jacks, one line in jack (for an MP3 player or other audio in), and speaker system.
No word if there is a mix out. But there is an extra audio port that online resources fail to mention what its purpose is. If it did do an audio mix out, then it could be a great podcast tool.