I used a custom case from A.B. Sutton for a while -- their simple slip for the original iphone. The thing to watch out for with these sleeves is how tight they are and whether or not there is a hole for the speaker. This is important because as I found out the hard way if there is no speaker hole you will not be able to really hear your phone ring, and you will miss calls. The alternative is to put your phone in upside down, but in the case of the Sutton piece it was so nice and tight that the case would lower the volume of the phone as it was inserted. So again, even with the phone upside down, you couldn't hear it ring. I love the simplicity of the slip type cases but many of them are not thoughtfully designed. (ps I note the Sutton case for the 3G now has holes for the speaker -- eureka! But not enough for me to get over my annoyance with them for their original design!)