[SalesForce] How to capture signature in Salesforce1 (Mobile App)

I was having the issue where the Detail Link in the email template was just taking me to the contact summary on SF1. In using the link from RichClark it worked for me. I just changed it to point to the contact detail page like this...

com.salesforce.salesforce1://entity/view?entityId={!Contact.Id}

You can access the camera from a Salesforce1 app, using the HTML <input> tag with accept="image/*" to access either the camera or photo library, for example

<input id="photoFile" type="file" accept="image/*"/>

You can then use the HTML5 File API to upload image data. Here's an example using the Force.com REST API - you would change this to process the QR code as necessary.

$(document).ready(function() {
  $("#photoFile").change(handlePhoto);
});

function handlePhoto(evt){
  var file = evt.target.files[0];
  var reader = new FileReader();

  reader.onload = (function(theFile) {
    return function(e) {
      // Extract raw base64 data from data URL
      imageData = e.target.result.split(',')[1];

      forcetkClient.create('ContentVersion', {
        "Origin": "H",
        "PathOnClient": file.name;,
        "VersionData": imageData
      }, function(data) {
        $('#status').html("<p>Uploaded image</p>");
      }, function(error){
        alert(JSON.stringify(error));
      });
    };
  })(file);

  reader.readAsDataURL(file);
}

The Dreamforce 2013 session Only One Cure for the App Boogie Fever demonstrates this technique; the code from the session is on GitHub.