Do you have an iPhone? I'm considering getting one since there are so many awesome applications out there nowadays! If you have an iPhone, you can go to iTunes and download the "Sephora to Go" app, which is FREE.
Once you do that, bring your iPhone to a Sephora near you and show an employee to get your FREE iPhone case (available for iPhone 3G, 3GS and iPhone 4)!
Click here to download the iPhone app from iTunes.