QR Code Generator
You can scan these to read them on Google's camera app (in the "lens" mode) on Android or the default camera app on iPhone or iPad.
Type some text, your QR code generates as you type!
You can also create a QR code for your WiFi information. Scanning it will connect you to the associated network, if it is in range. The QR code is generated entirely client side, you can vet the code here.