Rarely do you want to find just one instance of a word or phrase in Word. Instead of trying to keep Word 2008's Find and Replace dialog showing while searching, which can be awkward on a small screen, try the Next Find control. After you've found the term you're looking for once, click the downward-pointing double arrow button at the bottom of the vertical scroll bar to find the next instance of your search term. The upward-pointing double arrow finds the previous instance, which is way easier than switching to Current Document Up in the expanded Find and Replace dialog.
From Jeff Carlson