Case-Mate let us know about their latest release dubbed the Case-Mate I.D. The case has a built in card holder which can hold up to 2 credit or ID cards. It also supposedly protects the magnetic strip on your credit card. It only adds 2.5mm of thickness to the phone while protecting it from dings and scrapes.
The Case-Mate ID is selling on their website for $29.99 for the BlackBerry Curve 8300, 8520, 8900, the BlackBerry Tour 9630, and the BlackBerry Storm2 9550. The 9550 and 8900 models are not available just yet but will be coming very soon.
Find them at the links below:

burnsie Not Registered
Posted: December 28, 2009 at 12:12 PM EST from my BlackBerry 9000
That’s actually a great idea! Shame there isn’t one for the Bold
mike068 ( View Profile) Beginner - Posts: 126
Posted: December 28, 2009 at 1:59 PM EST
Ill agree with burnsie this is a very good Idea I may have to look into getting one of these.
joes Not Registered
Posted: December 28, 2009 at 2:07 PM EST
smrtcase makes an alternative version with simpler access, but still a bit pricey imho
http://www.smrtcase.com/products/
SirPedro ( View Profile) Newcomer - Posts: 20
Posted: December 28, 2009 at 5:39 PM EST from my BlackBerry 9700
If they have one for my 9700 Bold Ill get it. Otherwise….. :/
camshafter ( View Profile) Newcomer - Posts: 29
Posted: December 28, 2009 at 8:49 PM EST
i like…………….i did see somewhere where somebody else made something like this but not as sleek and i think it was more of a rubber
c0rinne ( View Profile) Enthusiast - Posts: 374
Posted: December 29, 2009 at 1:10 AM EST
Considering I always leave my berry lying around, I’d never risk it.