Thanks to Twitter, I have a new favorite iPhone app. And at the moment, you can download it for free. I find store reward programs and membership passcards incredibly annoying. For me, its not some privacy issue or that I mind being marketed to or even someone having info about my purchases - for me, its the annoyance of carting around a whole slew of cards in my wallet. Go figure, there's an app for that. It's called CardStar, and all you have to do is enter your membership number and it generates a scanable upc code, so you don't have to carry around a bunch of cards anymore. There was a time when I would have been reluctant to whip out my phone like that, but its to the point that iPhones are pretty common, so it feels a lot more comfortable to do so now. So far, its always worked for me. Have a favorite app? Let me know, I'd love to hear about it.