Columnist Barry Saunders finds fault with the word ginormous and wishes editors would not allow such coinages into the pages of dictionaries. John McIntyre, who writes You Don't Say at baltimoresun.com, explains that lexicographers are not legislators. They describe what is going on with language; they do not put a stamp of approval on coinages merely by adding them to the dictionary.
Of course, I don't recommend using "ginormous" in a news story or in an academic paper. The New Oxford American Dictionary's entry for "ginormous" notes that it is "informal, humorous." That's guidance that writers can heed. And if you are on a job interview, it might be best to describe your capacity for hard work with a more formal word -- enormous or boundless, perhaps.