Recently purchased and received a 2800mah battery and extended battery cover off ebay for $12.99 plus 2.99 shpg. Since it shipped to and from NJ I had to pay about a dollar and change in tax, but came out under $20. So far so good with the battery and the cover. Funny, the cover for the extended is more sturdy that the original battery cover. I searched the listings for the flat full rectangle extended cover with the little "feet" - actually tiny knobs that stick out on each corner. Some of the covers were slanted on two sides and I was afraid it would cause the phone to wobble a bit when laid on a flat surface on its back.
My thoughts: Great battery! Sturdy cover. Only about 1/4" extension - honestly, I expected much worse so I'm pleasantly surprised. The flat extended cover matches the phone perfectly and the phone still fits into my BodyGlove clear face pouch. But, most importanly, I can run BeeJive all day without draining my battery. Ya gotta love that