Does anyone know a relatively easy way to do it? is there a free way to do it?? 
I tried searching for topics but nothing came up.
Here is a website with a tutorial to do a watermark in Photoshop and Microsoft Word. Hope this helps.
http://video.about.com/graphicssoft/Watermark-Images-in-Photoshop.htm
http://wordprocessing.about.com/od/microsoftword2007/a/2007watermarks.htm
I just thought I'd let you know that doesn't stop stealing. A person can easily remove it. Not only can they remove it, they can put their own stamp on it. There was a thread on here about a bakery that did just that but it's gone now. A stamp might deter the unsavy. But stamps are not much of a security.
Melvira taught me how to do it, maybe you can ask her?
Putting the big 'M' light in the sky........calling MELVIRA for help!
GL
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