I run a motorsports photography forum and we produce a book each year, via BLURB. Unless you have an investor, this really is the only way to do it, as the only cost to produce the book is time. For the book that my forum produces, we accept images from anyone who is willing to submit and ensure that everyone who submit's get's the same amount of space as each other. Obviously, the forum is small, so this is not a hassle (I think from memory, last year each person could put in 4 images).....so doing one for APUG may not be as straight forward as that!
That being said, how many people would actually submit photos? I suppose you would need to decide whether this is an exercise where as many people are represented as possible, or whether this is a 'The best of APUG'.
For this to work, though, you really need one committed person to co-ordinate the whole project. Sure, they can deligate tasks to willing participants and find other ways to decide who gets included or not.