Rexcel is a rails plugin made to create custom and stylish excel files from your applications.

It is inspired by Brian P. Hogan's excel plugin (http://www.napcsweb.com/blog/2006/02/10/excel-plugin-10/) that provides a quick an easy way to export your object collections to an excel workbook. 

See Rexcel documentation and example on:
http://www.xaop.com/blog/2008/12/23/rexcel-plugin/