If a video or photo has already been uploaded by you into your own account from the iPhone, email or desktop, you can set or edit the location of the video or photo.

Touch the small thumbnail in the Uploaded area for the video or photo for which you want to set or change the location.

This will take you to the video or photo detail page where you will see a video thumbnail, comments, etc.

Touch the "Edit" icon (just below "Comment"). You will see a new page where you can "Change Location" for your video or photo.

Touch this button; on the next page, move the red map pin around by touching and dragging it until it moves to the set or changed location.

Touch "Save" on the "Change Location" page.

Touch "Editing [video/photo] title} button (upper left).

Touch "Save" once again and you are done.

If you are so inclined, return to the detail page for your video / photo and touch "Map It" to see your media on a map (to confirm your changes).