The Random Signature Script allows you to create a signature image that changes every time the image is reloaded. You can upload pictures and also delete them from your random signature. You need to create an account to get started.

Just a note, if you upload your picture and it doesn't display on your Random Signature, try just viewing the picture on it's own. If you get a error, it means the webserver can't process your picture file, so try changing the format to another format.