Sound Perfume is a pair of glasses, developed in Japan, that stores eight solid-state perfumes which can be emitted when you meet someone. This helps you remember the encounter more clearly, by associating a particular smell with that person.
Sound Perfume uses a heated coil that brings the solid-state perfumes up to 46 degrees Celsius – where they oxidise into scent. The glasses even let you sync a photo from your phone with all the scent data of the person you've just met.
Researchers at the Spanish Museum of Natural Sciences have found our olafactory sense to be one of the strongest for memory. They also believe the sense of smell is key in social interactions. So a team from Keio University in Tokyo and the National University of Singapore created Sound Perfume glasses in order to intensify that scent encounter and let us get it all into the virtual world using our synched phones.
There are even plans to use the Sound Perfume technology to enhance haptic, thermal and olafactory sense feedback for gaming. Here's a (school-like) video explaining it more.