Chrome only: If there's an app, a link or anything else on the web you want to quickly pull up on a smartphone or send to friends, QR Code Generator gets you there with just a right-click from Chrome.
The extension makes use of Chrome's new right-click API for extensions in convenient fashion. Right-click any link or highlighted URL inside Chrome, and you'll get a "Generate QR Code" option. Click it and a QR code you can save or link to a friend pops up. Most modern smartphones have apps that can scan for QR codes these days, and usually for free in their respective app stores.
QR Code Generator is a free extension for Google Chrome. For a no-extension, no-Chrome solution, try the Goo.gl QR code bookmarklet.
QR Code Generator [Google Chrome extension gallery]