LOL, love Doc's one, simple if you can design it, also adding your Forum name can easily be achieved then It can be printed. Or loads.
Of course you can always pop down to your high street and into any printers shop and get some made up, just thought was a good idea for individual tossers, not forgetting the many quality stickers available from this forum, which I have previously purchased from.
Cloth badges also a great idea, back patch or sleeve sew on badge of honour. That would need to be a good seamstress or a company that deals in making them. (will look into that later)