We describe how to realize magnetic and magneto-optical confinement of ultra-cold atoms in a torus with adjustable diameter and how an elliptical cloud of ultra-cold atoms can be adiabatically transformed to have a toroidal shape. An experiment with cold 87Rb atoms demonstrates the feasibility of shape transformations. These techniques can be used for atom interferometry and quantum computation. PACS 03.75.Be; 32.80.Pj; 03.67.Lx