Windows/Linux/iOS: Ever wish you could scan QR codes and other barcodes from your computer, without pulling out your phone? (Maybe you miss your old CueCat?) ZBar is a simple cross-platform tool that scans barcodes from images and webcams.
We've shown you how to make your own QR codes and how to use Goo.gl as a QR code generator, but you still need a way to read the codes you or other people make. ZBar is a simple to use tool that makes reading them (and other types of codes) command-line easy (which is to say, simple if you're comfortable with the command line). It's available in most Linux distributions (sudo apt-get install zbar-tools in Ubuntu), Windows users can download it from its Sourceforge page, and an iOS version that uses your iPhone's camera is available on iTunes.
On Windows and Linux, ZBar installs two command-line programs: zbarimg to scan barcodes in image files and zbarcam to read barcodes from your webcam. It's a bit on the geeky command-line side of downloads, but ZBar also has an installation and usage guide aimed at helping Windows users who are uncomfortable with the command prompt.