I would have definitely had these balloons at my party back in July (http://arceart.blogspot.com/2009/07/creative-giant-cakes.html) if they were out then.
These balloons have a small LED in them which will keep the balloon alight for 15 hours, easily enough time for a party.
Want to get them?: http://www.firebox.com/product/2477/illoom-balloons?via=sbp
