The website "Revolver Map" as a very clever map to show who visited your website. It is a free tool and it looks very nice. See above who visited wesdotphotography since I installed this map.
This is a very highly customizable map, mine shows depth of the oceans as well as snow caped mountains and poles. It will also change based on the seasons of the year. It can shows flag and locations of your visitors as well.
Visit http://www.revolvermaps.com/?target=setup for more detail.