a simple refactoring.

easypaginate.js

/*
 *  Easy Paginate 1.0 - jQuery plugin
 *  written by Alen Grakalic    
 *  http://cssglobe.com/
 *
 *  Copyright (c) 2011 Alen Grakalic (http://cssglobe.com)
 *  Dual licensed under the MIT (MIT-LICENSE.txt)
 *  and GPL (GPL-LICENSE.txt) licenses.
 *
 *  Built for jQuery library
 *  http://jquery.com
 *
 */

(function($) {
          
    $.fn.easyPaginate = function(options){

        var defaults = {
            step: 4,
            delay: 100,
            numeric: true,
            nextprev: true,
            auto:false,
            loop:false,
            pause:4000,
            clickstop:true,
            controls: 'pagination',
            current: 'current',
            item: 'sprite_icones item',
            randomstart: false
        }; 
        
        var options = $.extend(defaults, options); 
        var step = options.step;
        var lower, upper;
        var children = $(this).children();
        var count = children.length;
        var obj, next, prev;
        var pages = Math.floor(count/step);
        var page = (options.randomstart) ? Math.floor(Math.random()*pages)+1 : 1;
        var clicked = false;

        var stepbutton = function(event) {
            clicked = true;
            show(event);
        }
        
        // varias porquisses... precisa de refactoring!
        function show(event) {
            if (event && $(event.delegateTarget).hasClass('off')) {
                return;
            }

            if (event && $(event.delegateTarget).hasClass('next')) {
                page++;
            }

            if (event && $(event.delegateTarget).hasClass('prev')) {
                page--;
            }

            clearTimeout(window.carouselTimeout);
            lower = ((page-1) * step);
            upper = lower+step;
            $(children).each(function(i){
                var child = $(this);
                child.hide();
                if(i>=lower && i<upper) {
                    setTimeout(function() {
                         child.fadeIn('fast');
                        },
                        ( i-( Math.floor(i/step) * step) )*options.delay
                    );
                }
                if(options.nextprev){
                    if(upper >= count) {
                        next.addClass('off');
                    } else { 
                        next.removeClass('off'); 
                    };
                    if(lower >= 1) { 
                        prev.removeClass('off');
                    } else {
                        prev.addClass('off'); 
                    };
                };
            }); 

            $('li','#'+ options.controls).removeClass(options.current);
            $('li[data-index="'+page+'"]','#'+ options.controls).addClass(options.current);
            
            if(options.auto){
                if(options.clickstop && clicked){}else{ window.carouselTimeout = setTimeout(auto,options.pause); };
            };
        };
        
        function auto(){
            if(options.loop) if(upper >= count){ page=0; show(); }
            if(upper < count){ page++; show(); }
        };
        
        this.each(function(){
            obj = this;
            
            if(count>step){
                                
                if((count/step) > pages) pages++;
                
                var ol = $('<ol id="'+ options.controls +'"></ol>').insertAfter(obj);
                
                if(options.nextprev){
                    prev = $('<li class="sprite_icones arrow prev"></li>')
                        .appendTo(ol)
                        .on('click.prev', stepbutton);
                };

                if(options.numeric){
                    for(var i=1;i<=pages;i++){
                    $('<li data-index="'+ i +'" class="'+ options.item + '"></li>')
                        .appendTo(ol)
                        .click(function(){  
                            clicked = true;
                            page = $(this).attr('data-index');
                            show();
                        });
                    };
                };

                if(options.nextprev){
                    next = $('<li class="sprite_icones arrow next"></li>')
                        .appendTo(ol)
                        .on('click.next', stepbutton);
                };
                show();
            };
        });

        window.cleanCarouselTimeout = function () {
            $(children).fadeIn('fast');
            clearTimeout(window.carouselTimeout);
        }
    };

})(jQuery);

paginator.js

(function ($) {
    $.fn.paginator = function (config) {

        var items = $(this).children(),
            pages = Math.floor(items.length/config.step),
            currentPage = 0,
            self = this,
            $paging = $('<ol id="pagination"/>');

        items.each(function () {
            $(this).hide();
        });

        function display (items, currentPage) {
            $.each(items, function () {
                $(this).hide();
            });
            var offset = currentPage * pages;
            var itemsToDisplay = items.splice(offset, config.step);
            $.each(itemsToDisplay, function () {
                $(this).fadeIn('fast');
            });
        }

        function pageClick(event) {
            $(event.target).parent().children().removeClass('current');
            $(event.target).addClass('current');
            var page = $(event.target).prop('data-index');
            display(items.slice(0), page);
        }

        function buildPaging() {
            for (var i = 0; i < pages; i++) {
                var $li = $('<li class="sprite_icones item" />').bind('click', pageClick);
                $li.prop('data-index', i);
                $paging.append($li);
            }
            $paging.insertAfter(self);
        }

        buildPaging();
        display(items.slice(0), 0);
    }
}(jQuery))