Nowhere in good writing do utilize and utilization serve a better purpose than use. The former two words, which appear far later in our language (c. 1800 vs. c. 1200), now function as perfect synonyms of use—redundancies that do not improve our language. Perhaps due to their French origin, utilize and utilization are often mistaken as more formal alternatives to use, a mistake even the New Oxford American Dictionary makes. (For the curious, Merriam-Webster’s Collegiate Dictionary does not make this error.) No evidence suggests that the longer words make writing any more formal. In fact, they make it far uglier. Always prefer the briefer, more common use to its longer, less common, clunkier alternatives.
As Wilson Follett states in his usage dictionary, “If utilize and utilization were to disappear tomorrow, no able writer of the language would be the poorer.” Write as if only use exists.