The Windows Personalization Gallery already has some amazing images to choose from, and computer users visit the site on a regular basis to find new wallpapers and themes to customize the look of their screens. But with this open call, we all have the potential to share our images with a huge audience. The details are on the submission page, but in a nutshell, all you have to do is e-mail your uncompressed image to winpgal@microsoft.com with your name, e-mail address, website address (if you have one!), and a brief description of your photo. They ask that you submit one image per e-mail, so if you have a dozen to share, you'll need to do 12 e-mails, but other than that, the process is very straight forward. If you do submit multiple images, they may even be combined into a Windows theme of your work. For more information, checkout the FAQ on the program.
For an aspiring photographer, this really is a great opportunity to get your work in a highly visible place and in front of a lot of people. I know when I get the chance, I'm going to pair through some of my travel photos and hopefully find a few good ones to share.