We've just released our "fork" of the acts_as_solr plugin that we've been using for a while now to power the full text search on our projects. The fork features some changes to the way configurations are made, updates Solr and the Jetty HTTP server, better error handing, is fully compatible with will_paginate view helpers and :page/:per_page options and we feel it's a great option to the Rails full text search plugins.
Obviouly the plugin keeps one of the best features that is the live index update (no need to write cron tasks or anything to update your models, once your active_record object is saved or updated it's sent to be indexed by Solr).
If anyone is interested in checking it out, here's our sample tutorial at GitHub - http://wiki.github.com/mauricio/acts_as_solr
And here's the plugin repo - http://github.com/mauricio/acts_as_solr/tree/master
Cheers and I hope this email doesn't stars a flamewar