This paper describes two algorithms for laying out groups of objects in a 2D space-filling manner. Quantum Treemaps are a variation on existing treemap algorithms that are designed for laying out images or other objects of indivisible (quantum) size. They build on the Ordered Treemap algorithm, but guarantees that every generated rectangle will have a width and height that are an integral multiple of an input object size. Bubblemaps also fill space with groups of quantum-sized objects, but generate non-rectangular blobs, and utilize space more efficiently. Both algorithms have been applied to PhotoMesa, an application that supports browsing of large numbers of images. PhotoMesa uses a Zoomable User Interface with a simple interaction designed for novices and family use.