Churches all over the country are trying to figure how to use social media effectively. I've been thinking about this for years, and I'm still in the process of refining my thoughts on it (and as soon as my thoughts coalesce, the world of social media changes anyway).
We used likify.net to create the QR code. The nice thing about Likify is that is presents the user with a nice intermediate page that also maintains stats (and it's free). I can tell you that last week, two people scanned this QR code during worship. Not a huge number, but we'll see in the future if we begin capturing "likes" from people we might otherwise have lost contact with.
The other QR code we're using sends people to our Podcast page (fpce.podbean.com) where they can subscribe to my sermon audio feed. Again, we're trying to attract people into a situation where we have continuing contact with them. For straight QR codes, use the free QR code generator at http://qrcode.kaywa.com/ - simply enter a URL and it produces a QR code image for download.
I can imagine a day when we won't print paper bulletins anymore. Instead, the sanctuary will be adorned with posters displaying a QR code that takes you to an online location for the order of worship, and you'll follow along using your smartphone. Someday we'll be asking people to turn their phones on for worship.
It seems to me that we're still stuck in the mode of trying to make social media correspond to what we do already. I see churches using Facebook as nothing more than an email replacement. We're not being very effective yet at seeing what social media does on its own merits. If you want pure "push" contacts with your members, use email. If you want pure "pull" contact, that's through your Web site.
But one thing I've come to realize is that Facebook sits at the intersection of our public and private lives. As such, it is a relatively "safe" place for marketing - when someone "likes" your organization, they aren't revealing too much about themselves, and they control when they want to "disconnect" from your page. We should be able to take advantage of that in connecting with people on matters of faith at a stage when they may not yet feel comfortable disclosing themselves fully to the church but want to stay connected. When I send you an email I'm invading your space. A Facebook page update pushes to your fans' newsfeeds, yet somehow I don't think it feels intrusive. So we'll see how the QR code experiment goes. If it goes well, we'll have found a way to entice people to connect who might otherwise have come and gone unnoticed.