New Delhi, July 18 -- You're having coffee with a friend when you notice him lifting his hand to his mouth and whispering something you can't quite catch. You stop mid-sentence and give him a puzzled look, but the moment passes and he resumes the conversation. A few minutes later, it happens again.

Finally, you ask what's bothering him because he seems distracted. He holds up his hand and points to a shiny ring on his index finger.

An AI ring, he explains.

Something you said sparked a thought. Rather than risk forgetting it, he whispered it into the ring before it slipped away. The ring faithfully recorded it and beamed it back to its mothership app on his phone.

The AI ring belongs to a new category of gadgets that feels one step clo...