In lots of PC games, if you get bored and start poking through the installed files of your favorite title, you might look into the folders that have the sounds and video files. And I’d estimate that just over half the time, those video files will have a .bik extension. “So what?” you might think, “Those files are some kind of proprietary format that I can only look at when I’m playing the game.”
And that’s where you’d be wrong.
Those files are actually encoded with the Bink codec, which probably doesn’t mean that much to you. The important thing to know is that you can go to this site and download a player made specifically for playing those files (Windows only, I’m afraid).
Even better is that you can use that tool to convert an audio or video file into lots of other formats. All for completely free!
Which just happens to be my favorite price, especially for something that’s pretty useful.