Install placeholders on your own server.
git clone git@github.com:mrdink/placeholders.git
Once cloned, open /dist/placeholders/index.html then search and replace img.sixteenbit.com with the URL of your site.
Copy /dist/placeholders/ to the root of your server.
Forked from Dummy Image Generator
Code written by Russell Heimlich - http://www.russellheimlich.com/blog
Some code was written by Ruquay K Calloway http://ruquay.com/sandbox/imagettf/ to detect the text bounding box better (see comments in the PHP code.)