Nick Swan of Lightning Tools (creators of BDC MetaMan and general BDC gurus!!) has been busy writing a 2 part article on displaying your BDC data on an Application Page using a combination of WCF, BDC, Ajax and jQuery.
Head over to his blog for more information:
http://www.sharepointnick.com/archive/2008/12/11/business-data-catalog-ndash-doing-some-ajax-stuff-with-your.aspx
Nick Swans' Blog: www.sharepointnick.com
Lightning Tools: www.lightningtools.com