Though the main purpose of digital cameras is to record and display images, they are also devices with excellent spatial and temporal resolutions. We consider interface and sensing technologies as essential components for realizing human-centric ICT, and are working on several novel technologies utilizing digital cameras. In this paper, we introduce our gaze detection technology, a next-gen UI "FingerLink" to manipulate objects intuitively, a heart rate monitoring system using facial images, and a smartphone-based skin condition measurement system "Hada-memory (Skin memory)".