simple jQuery plugin that allows textareas to grow vertically when text is typed in

jquery.autogrow.js

/* 
 * Adapted from Autogrow Textarea Plugin
 * @see http://www.technoreply.com/autogrow-textarea-plugin/
 */
(function($) {
$.fn.autoGrow = function() {
	return this.each(function() {
        var txtArea = $(this);
        var colsDefault = txtArea.attr('cols');
        var rowsDefault = txtArea.attr('rows');
        
        var updateSize = function() {
            var linesCount = 0;
            var lines = txtArea.attr('value').split('\n');

            for ( var i = lines.length - 1; i >= 0; --i ) {
                linesCount += Math.floor( (lines[i].length / colsDefault) + 1 );
            }

            if ( linesCount >= rowsDefault ) {
                txtArea.attr('rows', linesCount + 1);
            }
            else {
                txtArea.attr('rows', rowsDefault);
            }
        };
        txtArea.unbind('.autoGrow')
               .bind('keyup.autoGrow', updateSize)
               .bind('keydown.autoGrow', updateSize)
               .bind('change.autoGrow', updateSize);
	});
};
})(jQuery);

live-sample.js

$('.js-auto-grow').live('keyup keydown change', function(evt) {
    var $this = $(this);
    var initAutoGrow = true;

    var events = $this.data('events');
    if (events) {
        events = events.keyup || [];
        for ( var i = 0, l = events.length; i < l; i++ ) {
            if ( events[i].namespace === 'autoGrow' ) {
                initAutoGrow = false; break;
            }
        }
    }

    if ( initAutoGrow ) {
        $this.autoGrow();
        $this.trigger(evt.type + '.autoGrow'); // re-trigger
    }
});

This solution is not bad. But I ended up doing my own for many reasons, explained here http://bit.ly/kBfnaD