Shameless plug, a while ago I wrote a micro rest api (ghost.py + flask) to take screenshots and optionally upload them to S3: http://gedrap.github.io/lightshot/

It still needs some extra work to be production ready though, please feel free to email me or create a github issue if you think it might useful for you :)

There is a capture_to[0] method that can be used to save a screenshot.

Btw, Thanks for telling me about Splash, I needed something that has support for Ad Block Plus rules.

[0] - http://ghost-py.readthedocs.org/en/latest/#ghost.Ghost.captu...