TechCrunch has an interesting article regarding German websites copying US originals (Web 2.0 in Germany: Copy/Paste Innovation or more?) . This is an idea that must have occurred to a few: take a reasonably rich country that likes to speak its own language, find a successful US idea and replicate.
The interesting thing is that this is actually successful, and that a US site takes time to localise and compete. Much of the success of a Web 2.0 site depends on user generated content and user collaboration, and without an initial critical mass of local users the site will not catch on locally. Perhaps as much as anything the local copies give their country a core cadre of native power users to collaborate, generate content and grow the site.