I spent few weeks working on this thing that I think could be pretty useful. I actually made this so I can replace the screen grab server that I use for PageRoost, which is currently just running on a machine in my apartment. I'd been thinking about making something like this for a while, but after recommending a client sign up for a similar service to generate PDFs, I decided I'd take a bit of time and see what would be involved in making my own service.
Turns out, not that much! A few weeks of work and a very slight bit of bootstrap customization later, and I had ScreenGrabAPI! It lets you generate JPG or PNG screenshots and PDF files of web pages. Probably not terribly useful to most people, but I'm pretty sure that it'll make some developers happy.