Best Mac Audio Recording Headsets for Voice and Podcasting

Sennheiser PC 146 Gaming Headset with Adjustable Boom Mic
The audio quality is more than competent for any podcast vocals. It’s not studio fidelity by any means, but the average listener will be largely unaware of any deviation. Largely, most podcasts do not rely heavily on audio fidelity. With the compression suffered by mp3 conversion, most listeners never hear the original audio quality anyways. 
Plantronics .Audio 655 USB Multimedia Headset
If you are overdubbing vocals to a musical project, a headset allows you to both listen to that music, as well as record while singing along. As mentioned, if you lack recording gear (headphones, mics, software, etc.), a head-set can provide a convenient and easy way to begin recording soon.