Borderless Quicktime Movies
Murphy Mac has a great screencast about creating Quicktime skins, but luckily it is a lot easier to create a borderless movie. It involves creating an image file and a text file to go with your movie, and then combining all three files into one borderless movie.
The first step is to find the dimensions of your movie. Double-click it to open it in Quicktime and press Command-I or choose "Show Movie Info" from the Window menu. The Movie Info window will show you the "Normal Size" of the movie in pixels. Make a note of this size.
Next, you will need to create a solid back image that is the same size as your movie. There are lots of ways of doing this, but here's a method that should be available to everyone. Download this image to your hard drive by clicking one the link and then choosing Save As from the File menu. Basically its a really big black rectangle.
The next step is to load up TextEdit and type the following lines:
Obviously it is a bit annoying to have three separate files to achieve this. The good news is that you can combine them into one file, but the bad news is that it requires Quicktime Pro ($30).
If you have Quicktime Pro, you can do this by choosing Save As from the File menu with the borderless movie open. Choose a file name and make sure you save it as a "self-contained movie", not a reference movie. The resulting file will still work fine if you delete the other files or move them about, meaning you can send it in emails or over the internet.
Now why would you want to do this I hear you ask? Honestly, there's no big reason apart from your movie will take up a bit less space and look a whole load cooler!