Last week I launched exif.alanreed.org an online Exif viewer. This tool allows you to view the metadata embedded within images such as brand, model, and serial number of the camera. Some cameras even store the latitude and longitude of where the image was taken. Cell phones especially store tons of good information in Exif.
I wanted to make this tool for a while and finally got the chance during a 20 hour drive to Orlando, Fl for the annual HTCIA conference.
Right now the tool only works for images, but in the future I hope to add the ability to extract metadata from other file types such as pdf, docx, and exe.