Particles bound to a fluid interface tend to attract one other via the so-called “Cheerios effect.”  In this talk, I will introduce two macroscopic interfacial systems where additional fields are introduced that can prevent particle collapse and lead to a variety of rich new collective behaviors. In the first part, I describe a system where millimetric floating disks are embedded with permanent magnets. The competing magnetocapillary interaction is shown to be governed by a Short-range Attraction and Long-range Repulsion (SALR) interaction potential that often arises in the modeling of microscopic colloidal systems. The emergent patterns formed by large collections of such particles are examined and analyzed. In the second half, asymmetric floating disks are shown to spontaneously self-propel or rotate when mechanically oscillated, in response to their self-generated capillary wave field.  Such capillary “surfers” and “spinners” hydrodynamically interact with each other via their collective wave field and exhibit a myriad of cooperative dynamic states.