Which extension files are allowed?

Images:
You'd better use the standard .jpg

Videos:
So far, only .avi .mpg .3gp are allowed.
However, if your video is in another format, you can download the following video converter which is free of charge:
http://www.applian.com/replay-converter/demo.php

More tips
When uploading an image or a video, you'd better include your name ( or initials) and the date in the file name. For example:
jjv-20070523-1.jpg
jjv-20070523-2.jpg