Phonak Invisity Flex Miniature Receiver
In the movie SkyFall (2012), James Bond (Daniel Craig) wears a Phonak Invisity Flex Miniature Receiver earpiece in the Macau Casino. He wears the earpiece in his right ear and uses it to communicate with Eve (Naomie Harris). We can assume that Eve also wears the earpiece although it's not shown in the film. Bond's earpiece can be spotted we he drops it in Eve's champagne glass. An expensive joke, since this earpiece costs £1100 - £1500 (with remote control) or $1290 - $1750. Widely available online at several stores including Raycom (UK), CreativeVideo.co.uk (UK), pro-sound.com (USA). threwaudio.com (USA).
The Invisity Flex In-Ear Receiver is designed for discreet prompting or communication for film, stage, television production or any situation where hidden communication is needed.
The same Invisity earpiece was also used by the SkyFall film crew in the scenes were Silva is locked in the glass chamber, to relay the lines of the actors outside the glass back to Javier Bardem. The earpiece is not seen in the film, but the side profile shot of Silva in Bond On Set - Filming SkyFall, page 107, the earpiece can just be seen sticking out of his ear.
More detailed information about this earpiece can be found on the official Phonak website.
Thanks to Jonathan Edwards for the ID