Not too long ago, I decided to send a brief snippet from a DVD to a friend of mine, hoping to illustrate a concept that we had briefly discussed. In the process, I made the acquaintance of dvd-ripping freeware.
Then it occurred to me that there were only-God-knows-how-many little scenes from DVDs that I could use--just a couple of seconds at a time--kind of like one uses quotes from other writers. So I've started building a little library of them, and will use them where I think effective and appropriate. I think that I am not out of line in saying that such usage is covered under fair-usage law.
It is true that the process I use to get these little clips leaves the sound ever-so-slightly out of sync with the video. Many times it's not terribly noticeable, but sometimes you'll notice that a clip is, perhaps, a syllable short or a syllable long. I apologize for that, but it's about the best I can do with what I've got--and I think it's pretty cool.