InfoWorld just posted a good and long article discussing the particular strengths and weaknesses of various NoSQL (aka, non-relational) databases. If you’re intrigued about what NoSQL databases are all about, and maybe even thinking about starting to play around with one, it’s well worth your time to read.
As for me personally, CouchDB and MongoDB are still most attractive, in some part due to their use of JavaScript and JSON, and in part because of existing PHP libraries for interacting with these database applications.
