The most popular, free, easy to generate & at a glance visualization tool are ClustrMaps. ClustrMaps is a real time combined hit counter and geographic visualization tool. Once website URL & Email is provided to ClustrMaps, a HTML code thus generated, needs to be copied into a web page or 'blog gutter'. This HTML code includes a link to a thumbnail geographical map image of the world which shows the location of the visitors arrived.

Another blog visitor's location monitoring tool is from VisitorMap.org which is also a free service. It is different from ClustrMaps as it shows the location of all the visitors to your site in the last 24 hours. It also provides a facility to users to customize the map  style, map size, visitor marker & color for the visitor markers.

Why Visitor Maps? 

Visitor Maps are quite helpful to:

• Know your visitors: Knowing who are your websites and blog readers.
  
  
• Target your content: Helps targeting your website and blog content ,adjust your content, your pitch, or your advertising according to the specific set of visitors.
  
  
• Show off your community: Developing a reader's community based on continents.
  
  
• Automatic: clicks optional: Each visitors to your site is automatically counted properly. Just visiting your site is sufficient. Of course, visitors can optionally click on the little thumbnail map widget and be taken to a large world map view for additional detail.
  
  
• Speedy, scalable: Knowing the numbers of visits from a specific part of the world.

Check 1: To start with first Register to http://digg.com/  to have an digg account & enter the digg world.( If already registered, skip this check)

<div style='float:right; margin-left:10px;'>
<script type='text/javascript'>digg_url = '<data:post.url/>';</script>
<script src='http://digg.com/tools/diggthis.js' type='text/javascript'/>
</div>