The stars came out for Galaxy last night. (Pun, depressingly, intended.)
The Galaxy Gear allows users to access emails, texts and even make phone calls - without touching their mobile.
It works via a Bluetooth connection with the new Samsung Galaxy Note 3 phone.
Presenter Jonathan Ross, former track cyclist Victoria Pendleton and model Donna Air were among the stars who attended the preview party at the Radio Rooftop Bar in central London.
Ellie Goulding performed at the event, while Daisy Lowe was the DJ. The party was hosted by Vernon Kay, who joked that he was a fan of the smartwatch, which also features a camera, because "everyone wants to be James Bond".
Simon Stanford, vice president of Samsung UK, said:
"We certainly believe this is the first truly mobile wearable technology in terms of the interaction you can get with this device.
"This particular product is going to change the way the connected world is going to start moving."
Goulding, who wore a tight-fitting white sparkly dress, performed hits including Your Song and Starry Eyed. Singer Sophie Ellis-Bextor, boyband Union J, socialite Peaches Geldof and JLS member Oritse Williams also attended the champagne-fuelled bash.
The Gear, which was launched at the Berlin IFA earlier this month, features speakers and microphones, meaning users speak into and hear from the device on their wrist instead of their handset.
It is designed to be used in unison with the Note 3 and Note 10.1 2014 edition - but will be able to work with other Samsung smartphones and tablet models by October.
It has a 1.9 megapixel camera capturing pictures and video. The Gear's battery lasts for more than 25 hours with each charge.
The recommended retail price for the Gear is £299, while the Note 3 costs around £599.