In order to deliver relevant regional results when searchers have "local intent", the search engines need to be able place your business geographically.  They try do this by a number of ways - but sometimes, they need help.

The first thing that the search engines will do is to try and associate your web site with a particular country/region.  They do this by looking at the physical location of your web site (i.e. where it is hosted) and the top level domain (TLD) of your site (e.g. ".co.uk").  

We have a free tool that can tell you where your site is physically hosted - Free Geo-location Tool.  This information will mainly dictate which of the regional versions of the search engine that your site will take a preference in - google.co.uk, for example, places a preference in rankings on sites with a ".co.uk" TLD and/or are hosted in the UK.

The issue is that where your site is physically hosted, is not the same as where your business is located.  The search engines understand this as well and to help place your site correctly, they will try to look for address data of some form in your web pages.  As you can imagine, this is pretty hit and miss when this information is buried in the regular html of your page.

The problem at the moment is that the industry lacks a standard for describing location on a web site that can easily be used by the search engines (and others) to help locate your business and by doing so, introduce more relevant locally-based leads to you.  

In addition to simply making sure that your address is everywhere on your site to increase the chances of Google understanding where you are located, there are a couple of structured approaches that can also be used. 

1. Geo.Position Meta Tags.   There are a number of meta tags that have been around for a few years that help define your business location, geographically. 

For Vertical Leap in the UK, for example, our meta tags would look like this:

<meta name="geo.position" content="50.79368,-1.09556" />
<meta name="geo.region" content="GB-POR"/>
<meta name="geo.country" content="GB"/>
<meta name="geo.placename" content="Portsmouth"/>
<meta name="ICBM" content="50.79368,-1.09556" />

As you can see, "geo.position" and "ICBM" are the coordinates of your business (longitude and latitude).  You can use a number of different mapping web sites such as MultiMap to get these details from your address.   And yes, ICBM does stand for Inter-Continental Ballistic Missile - its your "missile address". 

The other two ("geo.region" and "geo.country") are the "ISO-3166" standard codes that can be found from any number of web sites.

The final tag ("geo.placename") is your city, town or any other place name that describes your business location.

2. hCard Microformat.  You've probably seen the virtual business cards (vCard) that are sometimes sent via email or used to transfer data between two PDA's.  This kind of information is called a microformat - and the hCard standard is similar and quickly gaining in popularity for representing people, companies, organizations, and places in an open standard (XML/HTML) format.  

A lot of people are pushing the search engines to adopt hCard as a standard similar to how they all have adopted site maps.   I won't go into the detail of this standard in this post, but here's an example of how it looks in "raw" form for our own company:

<div class="vcard">
  <div class="fn org">Vertical Leap Ltd</div>
  <div class="adr">
    <div class="street-address">Customs House, 10 Hampshire Terrace</div>
    <div>
      <span class="locality">Portsmouth</span>,
      <abbr class="region" title="Hampshire">Hants.</abbr>
      <span class="postal-code">PO1 2QF</span>
    </div>
    <div class="country-name">UK</div>
    </div>
  <div>Phone: <span class="tel">0845 123 2753</span></div>
  <div>Email: <span class="email">info@vertical-leap.co.uk</span></div>
  <div>
    <span class="tel"><span class="type">Fax</span>:
    <span class="value">023 9286 3863</span></span>
  </div>
</div>

Currently, this information can be placed on your website just like any other text/html - but because it is standardised, it will be easier for the search engines to pick up.  I suspect that in the future, this information will be kept in a separate file and then referenced in the robots.txt file just as has been done with sitemaps recently.

Its important to note that neither of these approaches have been standardised or ratified yet - but I believe that they will soon (or certainly something like them).  So it makes a lot of sense to hedge your bets and start to use both when you are considering your Local Search Engine Optimisation process.

Local Search is important.  The majority of searches performed by users has "local intent" and the search engines know this and are actively working to deliver better local search results - they just need some help.