I worked on that with my little knoweldge of Adobe Flex, but it seems to work. While leaving a comment on this blog, not only you can add an image, but you can take a picture with the webcam too.
The feature is in testing mode, so very slow, but at least it works! When a picture is taken with the webcam, that picture has the precedence on the one selected from a file.
You can try it leaving a comment on this post… let me know if it works for you too!