David wants to improve his sound quality on Skype so he can record it, but he's finding he has to ask the person on the other end to record their side of the conversation. Leo says that's called double ended recording and it takes a lot of effort. It also doesn't work well half the time, but it is the best way to get professional broadcast like quality. Leo doesn't do this though.
The Chatroom says that MP3 Skype Recorder is another good option, and it's free. He should also check out the Netalyzer at UC Berkley, so he can analyze his connection and check for problems like buffer bloat.
For more information, check out our Wiki on How to be a Guest on TWiT. There's some great Skype tips there. But at the end of the day, the best thing he can do is have a wired connection and a lot of bandwidth upstream.