One of the common patterns in Here Comes Everybody is lightweight collaboration, not "Let's lock ourselves in a room for 5 days to work together" but "Let's make it easy for an individual to make a meaningful contribution with little effort." This patterns shows up in Linux and Wikipedia, where most of the contributors have made only one addition or emendation.
And now it's come to the book. Alan Connor has put up a Flickr page documenting typos in the first edition:
Now I know where to start for the second edition. As Eric Raymond might say, "Given enough eyeballs, all typos are shallow." Thanks Alan!