Inspired by robotic applications, we study the problem of sorting a set of items over a physical domain with mobile agents. Given m mobile robots and a grid where each cell contains a single element, the objective is to design algorithms that allow robots to cooperatively sort the elements over the grid in the minimum time. We assume a synchronous model where robots do not communicate, can carry up to c elements, and can move between adjacent cells in one unit of time (grab and release time is negligible). First, we show that any algorithm requires at least Ω(n²/mc) units of time to sort an n-element line (an n×1) and present an algorithm that sorts the elements in O(n²/mc) time. Then, we show that any n×1-grid requires at least Ω(n³/mc) time and present an algorithm that completes in O(n³ log n/mc) time. Our algorithms have an equivalent competitive ratio to Shear Sort [Isaacd et al., Proc ICPP 1986] with only m=n agents (compared to the n² processors required by Shear Sort). Finally, we present experimental results that show the capacity has very little impact on the overall runtime and that a simplification of the algorithm leads to better results.