Automating
This page accepts GET urls to automatically generate QR codes on page load. Use: http://w.undr.us/qr?url=YOUR_QR_DATA. This code does not clean any URL encoding, so escaped spaces ('+') will be included in the QR.
While URL's simply prompt the scanning device to open the link in a browser, QR's can contain links to Emails and SMS's via some simple formatting of the data:
mailto:email@domain.ext?subject=Email%20Subject
For pre-filled out SMS Messages, be sure to include the +1 US country code first for reliable scanning
sms:+10009995555?body=SMS%20Text