Been playing around recently with a PHP 5.3 data mapper library, would be interested to hear any feedback.

http://github.com/lox/pheasant

Still very early days, relationship support is still in proof-of-concept phase, but I'd be interested to hear what you guys think of the usage examples.

I'm well aware that there are two other excellent PHP 5.3 ORMs, both very similar to their Ruby counterparts (and both excellently engineered).

Basically where mine differs is in that I've tried to keep simple the declarations (which are in PHP), the database dependancy (which is Mysql and Innodb specific) and a build for a very light memory footprint.