Been a while since I've poked my head in here, but I was hoping to gather feedback on a couple of gems I've written for Rails 3, prior to Rails 3 leaving beta.
MetaSearch is an object-based search gem with a few nifty form helpers besides. You can read more about it at http://metautonomo.us/projects/metasearch/ (and see examples)
MetaWhere is basically the ActiveRecord 3.0 query interface on steroids. It gives support for complex conditions without writing SQL. It also provides improvements to order clauses and smarter inference of associations when nesting conditions hashes. Visit http://metautonomo.us/projects/metawhere/ for more info.
If you like what you see, I'd really appreciate your recommendation on Working With Rails. If you have feedback, please contact me via e-mail or Twitter. Thanks in advance!