I am starting to find this Digital Editions a useful tool as my pdf files are in the hundreds. It is relatively new, free and has an OSX and Windows version. It allows you to create categories and stores alias copies in these categories in a nice visual format. It is quite functionally basic but is ideal for the purpose of categorisation and easy access to these documents.
I often find myself creating many pdf’s in many of the softwares that I use for teaching, etc on the Mac and rather than print I often save as pdf from the internet, so for like people I think it is a good time saving tool well worth the free price.
Have a Good One STeve