Google's also been encouraging the use of QR codes. Their "Favorite Places" campaign puts QR codes in the windows of local businesses that point to their online listing page. Google's mobile operating system Android has also helped along QR code adoption. Since the Android Market is available only on the small screen, it's common for users to find an app by scanning its code from a Web page or another phone's screen. This t-shirt, which features a QR code promoting an Android-focused Web site, was a SXSW giveaway.