We present HuddleLamp, a desk lamp with an integrated RGB-D camera that precisely tracks the movements and positions of mobile displays and hands on a table. This enables a new breed of spatially-aware multi-user and multi-device applications for aroundthe- table collaboration without an interactive tabletop. At any time users can add or remove displays and reconfigure them in space in an ad-hoc manner without the need of installing any software or attaching markers. Additionally, hands are tracked to detect interactions above and between displays, enabling fluent cross-device interactions. The demo consists of the technical implementation of HuddleLamp's hybrid sensing and a Web-based architecture for installationfree ad-hoc collaboration. We demonstrate our implementation by showing a variety of possible interaction techniques.