The Internet of Things (IoT) is beginning to evolve and early solutions are now being implemented. We can find implementations in areas like logistics, farming, home automation and many others. But its restrictions become obvious as we try to connect solutions of different vendors, communities or standard groups. Apart from communication protocols new identity management mechanisms are crucial for a growing Internet of Things. This presentation discusses real project examples and introduces challenges coming from the Identities of Things as well as possible solutions encompassing identifier, mapping, discovery, authentication, authorization and privacy.