This has come up a couple of times before. According to my chat with Lobo today, not much is happening on this front. Since our client at Two Mice and a Strawberry has a need for this, we're diving in head first this week. Hopefully we'll have something that's worth contributing to core. Please comment below if you have any thoughts on the ideas presented here.
Blog posts by AllenShaw
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.