PDF Hammer. An online PDF file editor. Well actually it’s a part editor. You can add, delete and re-arrange pages, and soon you’ll be able to rotate and watermark them. But you can’t edit the actual pages themselves, which is a shame. I can see it being useful for last minute changes to a PDF you’ve received from someone else. You know, to add a new title page, change the order of a PDF presentation, that sort of thing. And because it’s online, you’ve got access to it from anywhere there’s a browser and net connection. Worth bearing in mind.