As we know build in full text search is currently limited only to MyISAM search engine as well as has few other limits.
Today Sphinx Search plugin for MySQL was released which now provides fast and easy to use full text search solution for all storage engines. This version also adds a lot of other new features, including boolean search and distributed searching.
A while ago I already wrote about Sphinx Search Egine, comparing it to built in FullText search and Mnogosearch. I guess I should soon repeat tests, adding Lucene to the list for complete picture.
And if you do not feel like patching MySQL or use MySQL 5.1 beta to use sphinx as MySQL Storage Engine you can still use it old fashion way as separate server.