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!"
If you have a small screen and sit far away, 720p is fine. If you have a huge screen and sit very close, the upgrade would be worthwhile. Here is a chart showing when you get the resolution benefit for a specific screen size/viewing distance.