I watched Adrian Madrid's [talk about MongoDB](http://mwrc2009.confreaks.com/14-mar-2009-19-36-mongodb-adrian-madrid.html) from Mountain West Ruby Conference 2009, and I like what I saw. [MongoDB](http://www.mongodb.org/display/DOCS/Home) seems like a very interesting document DB, with distinct differences from CouchDB. I haven't used Couch yet, so I don't know if these differences are good or bad. Anyway, I'm going to make a small project with MongoDB just to see how I like it: you can expect more posts about this in the next few days.