There is now an option to display the submitter's avatar next to his/her submitted content.  Below is an example of the [AVATAR] token being used in the List View template within the Search Directory module settings.

As with any token, the avatar's display location can be tweaked by moving its token around in the template.  Below is an example of how the avatar will display using the template above.

As you can see, this is a quick and easy way to spot user submitted content as well as identify the user.

Note: This feature has been added to the latest release of IndexItem as well.