In this new post to DZone.com Andy Hawthorne explains how to install MongoDB on OSX and get a local PHP working with it.

MongoDB is a document oriented, NoSQL database. It is gathering momentum and popularity amongst developers because it is flexible, and scalable at the same time. In this article I will describe how I got it set up and working on my Mac running OS X 10.8.2 and MAMP with PHP 5.2.17, and PHP 5.3.6.

They go a bit simpler route than trying to compile it yourself by using the binaries direct from the source. Instructions are included to test the installation, insert a record and how to install the MongoDB PHP driver for a MAMP installation. It's a shared object, though, so it's not specific to MAMP and could be installed even on the local OSX PHP functionality.