Check this out.
You can also generte a seal similar to this, with some customization of borders, images and the text.
Check the site Official Seal Generator for more details. I would have liked to see some Ajaxification, so that users can see the preview of the seal, as they change the various paramters.
Now why would I need this ? You can use it with the header image of your web site. Probably !! 🙂
Also don’t forget to check the home page, there are other image generators !
