1. A computer-implemented method, comprising: under the control of one or more computer systems configured with executable instructions, presenting a display by a first portable computing device to capture a plurality of images of an item at different points of view relative to the item; receiving the plurality of images captured in response to the prompting; generating a three-dimensional model of the item using information obtained from the plurality of images; storing the three-dimensional model in a database containing a plurality of three-dimensional models; determining that the three-dimensional model does not meet at least one model criterion; presenting a second display by a second portable computing device to capture at least one image of a view of a same type of item; and generating an updated three-dimensional model with information obtained from the at least one image captured by the second portable computing device; wherein at least one of the presenting the display by the first portable computing device and presenting the second display by the second portable computing device comprises: presenting instructions on a display of the first portable computing device or on a display of the second portable computing device to position the first portable computing device or the second portable computing device relative to the item when the updated model is incomplete, the instructions based, at least in part, on orientation information obtained from the first portable computing device or the second portable computing device.