A jQuery addon function for displaying the ID of a List Item in SharePoint on the EDIT (EditForm.aspx) or DISPLAY (DispForm.aspx) pages. See this blog post for more information: http://wp.me/p2kCXW-2u

SPAddIdToFormTable.js

/**
* @fileOverview A jQuery addon function for displaying the ID of a 
* List Item in SharePoint on the EDIT (EditForm.aspx) or DISPLAY (DispForm.aspx) pages.
* 
* @author Paul Tavares, www.purtuga.com, paultavares.wordpress.com
* @see http://wp.me/p2kCXW-2u
* @license Dual License support under MIT or GPL. User can pick whichever one applies
* best for their project and does'nt not have to contact me.
* 
*/
;(function($){
    "use strict";
    
    /**
     * Finds the form displayed on the EDIT and DISP pages and displays
     * the associated ID of the item at the top of that form.
     * 
     * @param {Object} [options]
     * @param {String} [options.field="Title"]
     *                      The field to use in finding the table.
     * @param {selector,HTMLElement} [options.field=null]
     *                      The table where the ID 
     *                      should be inserted. If defined on input, field input 
     *                      param is ignored.
     * @param {String} [options.itemId=itemId]
     *                      The item ID that will be displayed on the table.
     *                      Defaults to the ID parameter in the URL
     * @param {String} [options.idWrapper='<div style="font-weight:bold;font-size:2em;"></div>']
     *                      The HTML that will be used to wrap the ID when it is
     *                      inserted into the table/page.
     * 
     * @return {Object} jQuery
     * 
     * @example
     * 
     * $().SPAddIdToFormTable();
     * $.SPAddIdToFormTable();
     * $().SPAddIdToFormTable({ field: "Name" });
     * 
     */
    $.SPAddIdToFormTable = $.fn.SPAddIdToFormTable = function(options){
        
        var opt = $.extend({}, {
                field: "Title",
                table: null,
                itemId: GetUrlKeyValue("ID", false, location.href),
                idWrapper: '<div style="font-weight:bold;font-size:2em;"></div>'
            },
            options);
        
        if (!opt.field && !opt.table) {
            
            return;
            
        }
        
        if (!opt.table) {
            
            opt._field = opt.field.toString();
            opt.field = $("[title='" + opt._field + "']").closest('tr');
            
            if (!opt.field.length){
                
                opt.field = $("[name='SPBookmark_" + opt._field + "']").closest('tr');
                
            }
            
            if (!opt.field.length) {
                
                try {
                     
                    console.log("$.fn.SPAddIdToFormTable(ERROR) Unable to locate " +
                        opt._field + " on the page!");
                
                } catch(e) {}
                
                return;
                
            }
            
            opt.table = opt.field.closest("table");
            
        } else if (!opt.field) {
            
            opt.field = opt.table.find("tr:first");
            
        }
        
        opt.table.find("tr:first").before(
            opt.field.clone()
                .css("display", "")
                .find("td")
                    .eq(0)
                        .find("h3")
                            .empty()
                            .append("ID")
                            .end()
                        .end()
                    .eq(1)
                        .empty()
                        .append(
                            $(opt.idWrapper).wrapInner(opt.itemId)
                        )
                        .end()
                    .end()
        );
        
        return this;
        
    };
    
})(jQuery);