How 2 ANALYZE POPULAR SEARCH WORDS?

Hey PHPeeps - How would you analyze searched words to find/sort the most popular? Every time someone types something into our search box, we save it in a MySQL varchar field. They usually type multiple words. So... would you use a PHP loop to explode each varchar by " " into individual trimmed words, lowercase them, and ADD to an

ARRAY?    (searchwords[sex]++;  searchwords[mp3]++; etc...)

Or is there a better way? Any pre-made solutions to analyzing search box logs? Thanks! Derek Sivers list@hitmedia.com