As of now (version 3.1.5), CiviCRM limits finding and merging of duplicate records to users with the "Administer CiviCRM" permission. A recent thread on the forums points out that some organizations will want to allow that privilege to non-administrative users. Having a need for this myself, I'm looking for the best way to do it. If a reasonable solution can be found, I'm hoping the changes will make it into core at some point in the future.
Originally posted at TwoMiceAndAStrawberry.com. I recently had to modify CiviCRM to support a specific use case for a client. In this project I needed to allow the user to enter anything in the Individual Prefix field, rather than choosing from a list of options. The client in this case was very sensitive about presenting the individual's honorific precisely as the individual wants, so that "Dr.," "Rev. Dr.," and "Most Rt. Rev. Dr." should all be possible, along with anything else the user might want to enter.