You can make a simple query to determine the country a visitor to your web site is browsing from. You can then show them different content, according to the country reported, with a few lines of simple template logic.
This product includes GeoLite data created by MaxMind, available from http://www.maxmind.com
Basic example code to use in your .phtml template files:
$_ipHelper = $this->helper('sweetapple_geotargeting/data'); /* @var $_ipHelper Sweetapple_Geotargeting_Helper_Data */
$countryCodeFromIP = $_ipHelper->getCountryCodeFromIPAddress();
if( $countryCodeFromIP == "GB" ) {
//do something here, like load a specific static block...
echo $this->getLayout()->createBlock('cms/block')->setBlockId('home_page_message_GB')->toHtml();
}