Sanders asked me about this. I hope it helps.

First off...
...everyone should have a HD video converter by now. It's too easy.
Download. Install. Can convert anything under 3 minutes. No one has 3 minute lines.
http://www.xilisoft.com/hd-video-converter.html

Open converter. COPY the settings below.

Make sure your skate clips are always 1920x1080. That is the perfect size.
Make sure you are converting to (Profile) HD - H.264 Video (You'll essentially be converting to the AVC format).

Open Vegas 9 (should work for other versions of Vegas) > Project Properties > COPY settings


Render As > COPY settings
Make sure you are saving the file type as... AVC (mp4)


Render As > Custom... > COPY custom video settings
Make sure you go to the project tab and select "Best"


For people with HD PVRs. Watch this video.