you might find that using 'like %keyword% would actually work better than using the MySQL full-text search, cause it is actually quite limited (for starters, it only searches for words longer 3 letters (and you would be amazed how many good keywords are actually less than three letters))
The minimum length of words to be indexed is defined by the MySQL variable ft_min_word_len. See section 4.5.7.4 SHOW VARIABLES. Change it to the value you prefer, and rebuild your FULLTEXT indexes. (This variable is only available from MySQL version 4.0.)
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