a small suggestion if i may...
the main url can be hard-coded into the xml, so why not do that, and then users only need the last part of the url (and thus, don't need to go hunting embedded codes, and so on).
So, eg.
Code:
http://www.youtube.com/v/
is hard-coded
and the remaining file element is entered by each user
Would solve a lot of problems and make users lives easier