Of all the possible mistakes, incorrect spelling is often the most amusing grammatical error that can be found in a book, magazine, or other written work. I am often amused by the unintentional meaning when words are mis-spelled, or mis-used. For instance, in one of the early editions of Harry Potter and The Half Blood Prince by J. K. Rowling there is a line that is obviously wrong but rather amusing: "He tried to make a sound, even a grunt, but it was impossible. Then he remembered that some lizards, like Dumbledore, could perform spells without speaking." As most people are aware, Dumbledore is a wizard and not, as this sentence claims, a very talented lizard.
Comma splices are another common error found in written work. I have recently re-read the Little House on the Prairie series by Laura Ingalls Wilder. There is no doubt that Wilder is a well known author and her books have been read by generations of children. Unfortunately, the books are absolutely filled with comma splices. Of course, there is the fact that these books were written quite a few years ago to take into consideration. It is possible that some of the rules have changed since then, but in my opinion some mistakes are simply that, mistakes. Take, for example, this sentence: "And they were all clean, for Sunday." This sentence is taken from Little House in the Big Woods, the first book in the series, which explains the disjointed feeling of the sentences for the narrator is young and is recollecting faint memories. However, a young narrator does not excuse a comma for being somewhere a comma has no reason for being.
Typographical and grammatical errors in published works just go to show that no one is perfect. Errors can be made at any moment, and, like Kayla Gaffney says in her blog post of a similar topic, "The only way to master your corrections is to take time in your writing." If writers take the time to give their work the time it deserves than major errors can be avoided. However, no one is perfect and errors that are amusing can still pop up. For more hilarious written goofs take a look at Funny Typos, a blog devoted to the funny errors found in written English. A personal favourite is a Harvard University mug that reads "Harvard Universty." Maybe the "i" was cut due to budget cuts?