The trend of modern electronic systems, such as wireless and wireline applications, demands increasing reconfigurability, bandwidth, and dynamic range, but low power and cost. On the other hand, the technology scaling is slowing down its pace and incurs significant cost particularly for analog designs. Those factors have driven the design community to pursue both new circuit and system architectures towards unprecedented flexibility, performance, and low cost. Wouldn't it be nice to have an electronic system that can be arbitrarily configured based on user's needs? In this talk, we will examine several such attempts recently demonstrated by our group members that show the importance/effectiveness of re-thinking the analog-digital boundary in both circuit and system level towards this goal. Several initial silicon prototypes achieve encouraging performance and flexibility in comparison with the state of the arts. More importantly, they tout the potential for many future extensions, and hopefully allow a different thinking for analog-digital interface circuit architecture to transform future electronic system designs.