[chocolatkey]

A trick I've seen used at least one large site (feedly) use is piggybacking off Google's image serving infrastructure. Their ggpht/googleusercontent system gives you access to an image manipulation platform with more features than many open-source solutions (width, height, blur, rotate, frame, invert, etc). The only legitimate way to use it is through an application on their appengine platform, and I'm not sure why they don't offer it as part of the google cloud suite. Feedly seems to take the url in their appengine instance (seemingly dedicated solely to this, and redirects to a google URL which can then use the image manipulation features. Does anyone else here do something similar?

Edit: forgot to mention, the appengine documentation is very limited, and only mentions the ability for width/height resizing. Searching stackoverflow and other sites, however, reveals many other available modifiers

Edit 2: Also to mention is that the (ab)use of this service is quite popular with illegal sites. Who doesn't love offloading your image bandwidth to google's image proxies?