This is my experience with the (CandyShell Card case by Speck) and the Case-Mate ID case (Case-Mate ID Case). I hate carrying a wallet with me.
The CandyShell retails for $39.95 and the Case-Mate goes for $34.99. The CandyShell has three color options, the Case-Mate has nine colors. I went with black for both.
I have been using the Case-Mate case since I had the iPhone 3GS, and loved it since. I recently got the CandyShell case because I wanted a little more protection. The CandyShell also allows for 3 cards to be carried at one time, which allows me to go with a debit card, ID and a credit card in case my debit card doesn't work. The Case-Mate allows for 2 cards. Both of them hold one card with no issues. The CandyShell has a piece of plastic on the inside that keeps the cards from coming out on their own.
Ever since I started using these cases I always get two kind of comments, one is "awesome case, I like how you can carry your cards with you." The other comment is "you're out of luck if you lose your phone, you lose everything else with it." My response to the second comment is that women carry everything in their purse and no one gives them crap about that. I don't often lose my phone. I have actually never lost it, but if i say I never lose it i know tomorrow I will.
Here are two pictures of both cases side by side.
The CandyShell case is much bigger than the Case-Mate. It's very easy to put and take out the iPhone on the Case-Mate, not super easy on the CandyShell.
Here are some pictures of the Case-Mate:
The cards are very easy to put into the case, I find it sometimes hard to take them out. Especially when there are two in the case.
The openings for the Case-Mate make it very easy to reach all buttons and ports. Neither of these cases work with the iPhone dock. I had modified the dock to fit with the Case-Mate by taking off the cover of the dock, but it does not work with the Candy-Shell.
The Case-Mate allows the iPhone to keep it's nice look to it. It does add a little thickness but hardly any weight.
Some pictures of the CandyShell:
I use the normal iPod headphones and have no issues. I see where if you have a bigger headphone jack, it might be a little difficult.
The orientation lock is very easy to get to, not as easy as the Case-Mate.
It does not work with the dock, but the usb connector fits fine in there.
The cards are much easier to take out than the Case-Mate. Since the cards come out to the side, it's easier to actually grab the card.
The case to be is a little too big, but I was looking for more protection and this is the better case if you're looking for protection. I dropped my phone while in the Case-Mate case from about 3 feet and it the screen had the most famous crack you see on iPhones from drops. I haven't yet dropped my phone with the CandyShell. Since the case actually goes around the screen it does offer more protection.
The Case-Mate collects a lot of dust on the back of the phone, the CandyShell collects dust on the corners on the screen. CandyShell bother me more with the dust since it collects right on the screen.
If you want protection, get the CandyShell. If you just want to be able to carry your cards, go with Case-Mate.
The CandyShell retails for $39.95 and the Case-Mate goes for $34.99. The CandyShell has three color options, the Case-Mate has nine colors. I went with black for both.
I have been using the Case-Mate case since I had the iPhone 3GS, and loved it since. I recently got the CandyShell case because I wanted a little more protection. The CandyShell also allows for 3 cards to be carried at one time, which allows me to go with a debit card, ID and a credit card in case my debit card doesn't work. The Case-Mate allows for 2 cards. Both of them hold one card with no issues. The CandyShell has a piece of plastic on the inside that keeps the cards from coming out on their own.
Ever since I started using these cases I always get two kind of comments, one is "awesome case, I like how you can carry your cards with you." The other comment is "you're out of luck if you lose your phone, you lose everything else with it." My response to the second comment is that women carry everything in their purse and no one gives them crap about that. I don't often lose my phone. I have actually never lost it, but if i say I never lose it i know tomorrow I will.
Here are two pictures of both cases side by side.


The CandyShell case is much bigger than the Case-Mate. It's very easy to put and take out the iPhone on the Case-Mate, not super easy on the CandyShell.
Here are some pictures of the Case-Mate:

The cards are very easy to put into the case, I find it sometimes hard to take them out. Especially when there are two in the case.



The openings for the Case-Mate make it very easy to reach all buttons and ports. Neither of these cases work with the iPhone dock. I had modified the dock to fit with the Case-Mate by taking off the cover of the dock, but it does not work with the Candy-Shell.

The Case-Mate allows the iPhone to keep it's nice look to it. It does add a little thickness but hardly any weight.
Some pictures of the CandyShell:

I use the normal iPod headphones and have no issues. I see where if you have a bigger headphone jack, it might be a little difficult.

The orientation lock is very easy to get to, not as easy as the Case-Mate.

It does not work with the dock, but the usb connector fits fine in there.

The cards are much easier to take out than the Case-Mate. Since the cards come out to the side, it's easier to actually grab the card.

The case to be is a little too big, but I was looking for more protection and this is the better case if you're looking for protection. I dropped my phone while in the Case-Mate case from about 3 feet and it the screen had the most famous crack you see on iPhones from drops. I haven't yet dropped my phone with the CandyShell. Since the case actually goes around the screen it does offer more protection.
The Case-Mate collects a lot of dust on the back of the phone, the CandyShell collects dust on the corners on the screen. CandyShell bother me more with the dust since it collects right on the screen.
If you want protection, get the CandyShell. If you just want to be able to carry your cards, go with Case-Mate.