I downloaded Picasa (now on the mac) mainly because I am getting inconsistent colour/contrast punch via the Adobe apps. But it was interesting to see how tiny and simple it all is. It took a while to trawl through my computer hunting down all the images - but that's to be expected. It is a nice little app for a freebie and has some cool little features like the collage and movie tools.
Here is a quick shot of the collage tool using a few of the Michael Turner images - the position, resize rotate tools is cool.