Cloak of Anonymity
While wearing this cloak, you blend in with crowds. People ignore you, and overlook anything else that's strange about you. You could be a ten-foot-tall fanged demon who constantly weeps poison, and no-one would look twice when you walked past them in the marketplace. The cloak's magic can't hide you if you do something out of the ordinary.
If someone is specifically looking for you, you get a +4 bonus to checks to hide in the crowds.