I was about to use inArray (http://docs.jquery.com/Utilities/ jQuery.inArray) to determine if an element was in an array or not, but I realized I can't use it as a true/false response since it returns the position (and could return 0 if the element was found in position 0 - returns -1 if not found). I was expecting something with the same functionality as the PHP function in_array (http://us3.php.net/ in_array)
I know it's a minor point but wouldn't it be more intuitive if called arrayPosition? with a name like that I'd expect the functionality it has now.