Anytime a summary of a contact appears, the tags associated with that contact should be in the display. Could be an option by user as some may not want. Should be an option by tag as some tags are more meaningful than others. When I create a tag, I should have an option to indicate if the tag should be shown in contact summary.

Here's how it would be used. I have contacts all over the world, but want to send certain information only to those within the US. If I have a "tag" that indicates the person's location and that tag showed on the contact summary, I would not have to view their profile to see if they were a candidate for the US-only message.