Is there any way of doing this from the interface. I have lots of activities that need to be assigned to a small group of individuals. I want to assign these (currently unassigned ) activities to the corresponding contact. Can't do it through batch update or import, the assigned field isn't exposed.
If there is a way, we didn't find it, and that was partly why Fuzion put a bunch of time in to making it possible to assign/unassign/reassign Activities in Drupal using CiviCRM Entity Actions which is now a submodule of CiviCRM Entities, Views and Views Bulk Operations, in order to deliver a Calling Tool that could be driven from the Drupal front end. (Is there some way I can mark these types of answer as Drupal-only info?)
Since you mention import you could try using the csvimporter Extension, which does include many other Entities such as Activities and provides fields for eg 'assignee' when doing so.