these are my best websites i found that use the jquery for modal boxes:

http://www.ericmmartin.com/projects/simplemodal-demos/

http://nyromodal.nyrodev.com/ *

http://www.bitrepository.com/demo/modal_login/index.html#

http://www.sohtanaka.com

http://jqueryui.com/demos/dialog/#modal-form

http://corky.net/dotan/programming/jquery.dialog/dialog-demo.html