Bruce Williams of Naviance recently announced his RTex plugin. It exposes your controller data to rtex views that output LaTeX which is convereted to PDF.

To install you can use the plugin script:

ruby script/plugin install rtex

Or grab it from svn:

svn co http://codefluency.com/svn/codefluency/rails/plugins/rtex

People have used PDF::Writer to generated .rpdf views. Why go through LaTex to get to PDF rather than use PDF::Writer? Speed, says Bruce.