I was looking at some of the external batteries for the iphone and liked the look of those Mili ones where you slide the iphone into it and it locks into place. Curious, of those who have one, how secure is the phone in it? Is it nice and tight?

Also, I really like that IvySkin one where it encompasses the entire iphone, but that is only 3g compatible where mine is a 2g. Does anyone know of a similar one for the 2g?