A portable electronic device comprises a proximity-sensing user interface and a controller. Each such group assignment can change over time as a function of the assignment criteria, and the assignment criteria is configured so that every user is initially assigned to a predetermined one of the groups. Activation using a triggering force andor a constraint may be used to create varied activation rates in an SMP material and may be combined with temperature or other activation stimuli to create the varied activation rates. The starter hole and pilot hole are created by a longitudinal pushing force exerted on the bone screw by the surgeon. The location owner device uses the link to send to the LTSS information that uniquely identifies a device associated with a location provider selected to fulfill the transaction.