I've also created one using Wordle, which turns word clouds into art. (Believe, you can kill a lot of time on this site.)
You can look at that the Wordle cloud for Great Expectations here (where you can adjust the magnification) or in the screenshot below. (You'll probably have to collapse the profile panel at right in order to see the whole image.
As you can see, the two clouds accord fairly well. One thing that jumps out at me in both is the high frequency of proper names, though certainly the high frequency for "Joe" seems fitting.
One interesting difference is the absence of the word "know" from the TagCrowd cloud. (According to TextStat, "know" occurs a not inconsiderable 378 times in the novel.) I'm not sure what to make of this discrepancy. Presumably, TagCrowd is overlooking "know," regarding it as one of the more commonly occurring words in English. But in that case, why does it recognize "knew"?