SMate WordPress GeoIP Country Redirect plugin allows you to automatically redirect your visitors based on their country and a set of rules which you can define into wordpress administration panel.
Upgrade from 2.1 to 2.2 (23rd Jan)
1) allow to search country from dropdown (as well as page, category selects have been search enabled)
2) added confirmation on deleting a redirect rule
3) added a new feature to allow adding ?noredirect=true GET parameter to avoid being redirected
4) sorted countries alphabetically
5) overall improved user experience.