Did you ever try to download a trailer from trailers.apple.com? It doesn't work. Apple is trying to limit downloads to the iTunes application. Here's how you can change your user agent so the download works with wget.
Choose a trailer to download. For example the movie The Scientist produces the link
To get the correct URL you have to add the letter 'h' before the resolution. In our example the correct URL will look like this:
Now you can use wget with the parameter -U QuickTime/7.6.4:
wget -U QuickTime/7.6.4 http://trailers.apple.com/movies/independent/thescientist/thescientist-tlr1_h720p.mov
Have fun watching the trailers.