Site DB search using PHP/MySQL?

I'm looking to add a search facility to a website. I'd like to be able to search a couple of columns of a MySQL table on a full text basis. Is MySQL's included full text search any good? If so, how would I go about using it? Or if not, are there any good open-source alternatives? I only have a LAMP server to work with, so it would need to be PHP. Or failing that, am I likely to get reasonable results if I code one myself? Adding a table of keywords and a many-to-many joining table. Any pitfalls to watch out for or anything? Thanks