A little while ago I finally hit the 500 MB free storage limit of Mendeley, which isn’t surprising considering how I go about collecting research papers. Whenever I come across an article that looks like it might be mildly interesting / vaguely related to my work I copy it into a folder that Mendeley watches and that’s it. I have hundreds of papers that I’ve never looked at (and possibly never will). When I’m working on a project or article, I simply type the relevant keywords into Mendeley and it shows me all the papers I that might be useful to me. I know that this probably isn’t the best way to go about it (e.g. what about the serendipitous papers that I’d never find because I’m not actually looking for them i.e. relevance that I don’t know about?).
Anyway, when I hit the limit I thought I was finally going to have to do some tidying of my folder, until I realised that I could use Dropbox to store the PDFs and just tell Mendeley to watch that folder in Dropbox instead. Dropbox does a better job of keeping my articles synced across all of my devices (I don’t think Mendeley was designed to keep papers synced across multiple computers) and I can use Dropbox on my Android phone (Mendeley is still only available on the iPhone).