Let the hive mind of Engadget get that for you.
"I've found myself using my PC for a lot of conversations lately, and I'm also considering recording a podcast to share with anyone who will listen. There are tons of USB headset / microphones out there, and I'm hoping someone has some solid recommendations based on experience. I'll consider both headsets and standalone mics, by the way, but I'd like to keep the bill under $100 if possible. Help!"
What in the world is the point of this if existing handsets can't be upgraded? It's like AOL offering "high-speed dial-up" ... that doesn't work with current dial-up modems. Who in their right mind is going to upgrade to EDGE Evolution if, by the time it rolls out, every major carrier has 3G networks?