I've heard it said that there are a finite number of basic plots for a novel. Things like "the quest," "the coming of age," "the discovery," etc. ...that all stories at the simplest level fall into one of the set number of plot structures.

I've also seen books panned because "the plot is derivative." Eragon, which I happen to like btw, has dozens of one and two-star reviews on Amazon, the majority of which decry the story for being a rip off of LotR and Star Wars.

Thing is, Lucas "borrowed" much of his plot from Arthurian legend, and Tolkien, all-time-master-story-teller that he is, borrowed heavily from Norse traditions.

So my question is twofold:

1. Are there plotlines out there that have just been "done to death?"

2. What can an author do to revive or renew familiar plots so that they will feel original to the reader?