Is there a plugin or code somewhere that makes creating
reports in rails easy?
You may want to try Ruby Reports. It's not Rails code, but it's the raw
tools to do what you want.
From the site:
Ruby Reports is a software library that aims to make the task of
reporting less tedious and painful. It provides tools for data
acquisition, database interaction, formatting, and parsing/munging.
Designed to be extensible, it is possible to use Ruport for quick
specific tasks as well as to build robust reporting applications.