Video resolution

This is probably the main problem I'd like to solve ASAP - the presentations are recorded in a native PAL resolution (768x576) and until now I've resized it to 600x450 before uploading it to Mediacast. That's a completely acceptable resolution regarding shots of the talker, but is considerably worsens the (already quite poor) readibility of the recorded VGA signal (e.g. various demos etc.).

Together with switching to YouTube I planned to use the full PAL resolution, but no matter what I do the videos are automatically recored to 640x480. YouTube supports high definition videos, but it somehow does not work with PAL (at least I haven't found a way to play it in the native resolution).

I've considered recording with a HD camcorder but it is not a solution - the demos are (and will be) recorded in a VGA resolution. Do you have an idea ho to solve this? If yes, let me know.

Downloading the videos

Mediacast and YouTube work in a quite different way - Mediacast provides a "previes" and then you can download the video directly, but YouTube provides the videos solely through a player and there is no official way to download it. Which seems like a big disadvantage to me, as I'm wathing such videos when travelling bu train etc. - and that's not very convenient without downloading.