Am I late to the party on TVTropes.org? Don't click on it, unless you're willing to lose hours and hours.
For instance, Applied Plebotinum

Phlebotinum is the magical substance that may be rubbed on almost anything to cause an effect needed by a plot. Some examples: nanotechnology, magic crystal emanations, pixie dust, a sonic screwdriver. Oh, and Green Rocks. In essence, it is the stuff that makes the plot go. Without it, the story would grind to an abrupt halt. It's science, it's magic, it's strange things unknown to science - the reader does not know how Phlebotinum would work and the creators hope he doesn't care.

Via the institute of hybernautics in a post that was ostensibly about this:

Think of it like a movie. The Torah is the first one, and the New Testament the sequel. Then the Qu’ran comes out, and it retcons the last one like it never happened. There’s still Jesus, but he’s not the main character anymore, and the messiah hasn’t shown up yet. Jews like the first movie but ignored the sequels. Christians think you need to watch the first two, but the third movie doesn’t count. The Moslems think the third one was the best, and Mormons liked the second one so much, they started writing fanfiction that doesn’t fit with ANY of the series canon.

(Thanks, Mike)