At last a UK shop selling a Flash cart that works with both DS and GBA, heres more info:

<a href="http://www.baldbouncer.co.uk/catalog/product_info.php?ref=2&products_id=218&affiliate_b anner_id=1" target="_blank"><img src="http://www.baldbouncer.co.uk/catalog/affiliate_show_banner.php?ref=2&affiliate_pbanner_ id=218" border="0" alt="Flash 2 Advance Ultra 1 Gig USB Kit"></a>

<a href="http://www.baldbouncer.co.uk/catalog/product_info.php?ref=2&products_id=218&affiliate_b anner_id=1" target="_blank">Flash 2 Advance Ultra 1 Gig USB Kit</a>