One of the ironies and frustrations I find of working with open-source software is that things are changing so fast (yay!) that the documentation you find is nearly always out of date (boo!).
Trying to figure out how to get the rmagick component of the handy file_column rails plug-in to play nice, I came across numerous gruesome posts involving 3 hour sessions building rmagick from source, sacrificing goats, etc. Yikes.
Then I came across this great piece of news and suddenly things clicked into place. Ahhh.
Ten minutes later, a sprinkle of this, and I have thumbnail images all over my site. Too easy!