I came across this neat find this morning when I was needing to convert a PDF file that was too big to send through our fax service into something smaller. Zamzar is a free site that allows you to convert an astounding number of image, document, video and archive formats into anything else the site supports. The process is very simple: You select the files you want to convert, select what format you want to convert them to and enter an e-mail address where you will be told where to download the converted files.
They do offer a paid premium account but the free one has very generous limitations and will be more than enough for most people. I'm very impressed with how many formats they support and how the conversion of my particular file was done almost instantly. They do offer a strong privacy policy but even so, since you are sending your files to a third party for conversion, I personally would not use them for anything containing sensitive or confidential information but beyond that, this is a great service and one of those things you may not use often but which is very handy when you need it.
