If you own a website in a specific country but want to target outside countries, what's the best way to do this? Is it worth hosting mini sites in the target countries?
That's something you can consider, but if the sites are so small, it may not be worth it. As Robert Charlton says, if they're just acting as doorways to the other site, the site may lose credibility. However, not all webmasters have had this issue with the loss of credibility as long as there's a good amount of target key phrases and inbound links.
Another tip would be to try to get links from the target country to your main site. And if you have to, buy ask for links.
Eventually, when the tool works, you can use the Google Webmaster Tool feature that allows you to set the geographic target of your site.
And until then, recall this Google Webmaster Central Blog post where Google acknowledged that the IP address and TLD of your domain influence the rankings.
Forum discussion continues at WebmasterWorld.