If you're taken with collaborative composition, however, MixedInk.com looks like a pretty nifty tool! And this Inaugural Address project is an excellent demonstration of how it works. Here is the email from Slate.com:
A Message to Slate Readers
If you've ever wanted to be a presidential speechwriter, now's your chance: Go to the address below to collaborate with Washington, Lincoln, JFK—as well as other Slate readers—to write this year’s Inaugural Address.
Created in partnership with MixedInk, here's how this feature works: When you click on the link, you will be taken to a site where, once you register, you can start writing your own speech. But you won't be writing alone. As you compose, MixedInk's technology will search for similar words and turns of phrase from all 55 previous inaugural addresses, as well as contributions from other users, and tell you if anyone has had similar thoughts. You can then incorporate these into your own speech
(or decide to stick with your own words). You'll also be able to search for useful snippets of text yourself. The technology keeps track of authorship, and when you're done, you can share your speech with others, who can then borrow (or ignore) your handiwork as they see fit. They can also rate your speech and comment on it.
At the end of this process, which will last about two weeks, Slate will publish the speech with the highest rating. (We may publish a few interim versions as well.) Maybe it will be the one you wrote—with a little help from Jefferson, Madison, and FDR. And maybe President-elect Obama will decide to borrow from your speech—at least that part where you quote Lincoln—when he delivers his Inaugural Address on Jan. 20.