+1 for sphinx. It's fast and memory efficient, an in my experience rock solid. Comes with excellent python bindings, and if your python is django, there is als

+1 for sphinx. It's fast and memory efficient, an in my experience rock solid. Comes with excellent python bindings, and if your python is django, there is also a really nice django-sphinx project on google code. Solr is also good, but it does require java and behaves slightly differently. I would recommend you give both of them a look.