Free Software:
There are very many free software sites on the World Wide Web. I have chosen here to focus on just a couple of photo related free downloads, mainly because the display and organisation of photographs is such a big issue for almost everyone nowadays. What with camera 'phones and slinky slim digital cameras, you are bound to have many, many digital photographs to view and organise. Am I wrong? :-)
Irfan View is one of the most popular viewers worldwide. I have no hesitation in recommending Irfan View as I have been using it for years. It seems that no matter what media you wish to view, and no matter what format it is in, Irfan View can open and display it.
Picasa is a free software download from Google that indexes and organises your digital photo collection. You have to use this free software to appreciate its usefulness. Picasa will locate and organise the photos, even ones you have forgotten you have. There are also photo-editing tools built into the free software.
An option that is sometimes not considered but may result in saving money, is to upgrade your operating system. Modern OS like Windows Vista or the latest MAC Leopard OS have very sophisticated photo handling capabilities built in. So whilst you have to pay for the Operating System itself, whatever photo handling software that you get is a free bonus.
Another source of free software on the web is the Open Source community. A simple Google Search for Open Source Software will lead you to many sites offering free to use software. There is a definition of Open Source Software at Wikipedia and if you scroll to the end of the article you will see a huge list of resources to help in your quest for free and open source software.