#“Very cool, Inkscape can import a PDF so you can edit it”
A constant problem in dealing with design agencies and others is that most of them only deliver the print-ready or web-ready files (PDFs, JPGs etc) and don't give you the original source PSD, AI, SVG etc. This means that you always have to go back to them, even for the smallest tweak. We have an old flyer from a trade show last year and I want to do a quick re-spin for the lowest cost possible for a trade show next week. All I have is the PDF. For fun I tried importing it into Inkscape. And whaddya know, it works!
If you aren't familiar with Inkscape, it is a free vector drawing app for Windows, Linux etc. The big difference between vector drawing and bitmap drawing (like GIMP, Paint, Paint.net) is that you can scale vector drawings as much as you like and they stay smooth rather than bitty or pixellated. The Inkscape UI is an absolute horror and after listening to a podcast last year with the developers, that's not going to change since they think it's fine. But once you get the hang of it (and there are tons of tutorials), it's brilliant for doing vector stuff and then outputting PDF, EPS for print and PNG for web. I use it for a bunch of banner ads we have on a partner intranet and also for any logo requests we get for big signs at shows etc.
I was chuffed that today's PDF import worked. It's not ideal since it only sees some of the text as text and the rest as individual vector letters but it's enough to let me remove some extraneous bits and add others. I'll be shooting the output to a printer tomorrow.