Active development on Google Wave, a collaboration tool that used features of email, chat and document sharing, has been shut down. Google announced that the chief reason for discontinuing Wave was the low user adoption. The platform will live on within other Google projects, as well as the many portions of Wave that have been open sourced.
Gravatar is an attempt to allow users to have one globally recognized avatar. The service, around for several years, allows a user can set an image as an avatar and have it recognized on a variety of sites. Later, users can change an avatar once and have it change on every Gravatar-enabled site that they use. Though the service is somewhat well known, what is not is its robust API for developers to integrate the Gravatar service into their own sites.