Audio-Technica's ATR2100 Cardioid Dynamic mic is a great starter microphone if you're thinking of beginning your own podcast. I built a beginner setup for myself with this mic at the core after doing quite a bit of research of various podcasters, and have been happy with the results thus far.
The mic sounds great and is easy to setup -- I used it to record my end of the first two episodes at Too Many Comics.
Notable features, via Amazon:
- Handheld dynamic microphone with USB digital output and XLR analog output
- USB output connects to your computer for digital recording, while the XLR output connects with your sound system conventional microphone input for use in live performance
- Smooth, extended frequency response ideally suited for podcasting, home studio recording, field recording, voiceover, and on-stage use
- Built-in headphone jack allows you to directly monitor your microphone output without audible delay
- Cardioid polar pattern reduces pickup of unwanted sounds from the sides and rear