Few days ago, I wanted to turn a PDF document to JPG files so that I could insert the pages as figures in a Word document. Please do not ask why.
I was able to find a bunch of software to do so, free or not. But I did not want to download and install one of them for this one-time task.
Few days later, I came up with pdf2jpg.net, a free, on-line service to turn PDF to JPG easily.