Anyone used (or want to use) Xapian (or any other search engine libraries)?

[eluser]GlennJ[/eluser]
I'm creating a CI application at the moment and have decided that I will be using Innodb MySQL tables.

What this means is I'll not be able to use the MySQL full text searching, which isn't a bad thing as apparently it's not that great anyhow.

So, what do I use for a decent search engine?

I came across a few and wondered if anyone had used Xapian or any other search engine library?