La Laborotoire's cylindrical oPhone, invented by David Edwards and Harvard students Rachel Field and Amy Yin in the Paris laboratories, uses a tiny chip, the oChip, to produce scent signals using olfactive information, which are then sent out and received by connecting an app - OTracks - to Bluetooth.
Soon the chips will be able to send thousands of different smells to your mates, although it is not really clear why you would want to do this. The product will be out later this year and will come with two oPhones, to enable people to smell more than one smell at the same time.
However, it is more likely that the tech will end up in multi-media presentations so you can smell what is happening as you read a book or see a movie. Still it would be nice to send a smell of something I ate several hours ago to certain press offices.