A lightweight userscript to set the default viewing mode for YouTube videos to Theater Mode.

Doesn't use jQuery.

Differences between other userscripts:

• Youtube: Cinema Mode - This userscript uses cookies to set the mode to Cinema Mode (a.k.a. Theater Mode). This is very similar to my script, but this one has to reload the page once the cookie is initially set.
• YouTube Cinema Code - Script disables YouTube's SPF and requires jQuery and also does too many things (can be seen as a pro).
• Yays! - This used to be my favorite, but this stopped working for me awhile back. Script is also quite large.