Little FYI...the form builder has a field type called 'datestamp' and displays a date in dd/mm/yyyy. This is somewhat confusing as most people would read '04/06/2011' as April 6th and not June 4th.
Simple change...Go to edit the plugin
Find the file called 'formbuilder/js/calendar.js'
Locate the line...
document.getElementById(ths.opt["input"]).value = day + "/" + month + "/" + year; // Date format is :HARDCODE:
Make it look like...
document.getElementById(ths.opt["input"]).value = month + "/" + day + "/" + year; // Date format is :HARDCODE: