There are a gazillion photo organizers but I've never really got on with any of them - even Picasa. I was pleased to find Pictomio though, which aside from some weird geo-taggng guff is actually rather good and certainly worth a download. It needs a decent graphics card but ran fine on a three year old Dell with an ancient NVidia inside. I've written a how to workshop on Pictomio for Computeractive magazine.