As the battery for my iPhone 3G (soon to be replaced), seems to drain FAST, this is a great product for me.

Pros - it's a fast charge and a nice additional battery for when (playing Angry Birds) my phone battery is running low.  It's good to keep on hand and quite portable.

Cons - It doesn't suction to the iPhone 3G very well.  I assume this is because of the curved back, whereas the 4 is flat.

The adapter is really bright.  It glows blue and lights up my bedroom.  It's not appropriate to keep in a bedroom, or at least, never leave it plugged in at night.

My alarm doesn't go off when the battery pack is plugged in.  I don't know why this is, but it's happened a few times already.  This could just be a 3G problem though.

It's bulky.  If you keep your phone in your pocket, this will not work for you.  I found that I never plugged the battery pack in and carried it around like that.  I use it in the evenings when I'm sitting on the couch (playing Angry Birds) before bed so that I can get a full charge on my phone before bed.  I've seen others that are a lot less bulky.

All in all, it's a good product, but probably not something I would buy again due to bulk.  I would probably go for one of the more portable styles.
As the battery for my iPhone 3G (soon to be replaced), seems to drain FAST, this is a great product for me. Pros - it's a fast charge and a nice additional battery for when (playing Angry Birds) my phone battery is running low. It's good to keep on hand and quite portable. Cons - It doesn't suction to the iPhone 3G very well. I assume this is because of the curved back, whereas the 4 is flat. The adapter is really bright. It glows blue and lights up my bedroom. It's not appropriate to keep in a bedroom, or at least, never leave it plugged in at night. My alarm doesn't go off when the battery pack is plugged in. I don't know why this is, but it's happened a few times already. This could just be a 3G problem though. It's bulky. If you keep your phone in your pocket, this will not work for you. I found that I never plugged the battery pack in and carried it around like that. I use it in the evenings when I'm sitting on the couch (playing Angry Birds) before bed so that I can get a full charge on my phone before bed. I've seen others that are a lot less bulky. All in all, it's a good product, but probably not something I would buy again due to bulk. I would probably go for one of the more portable styles.