Geo-targeting, and the customer experience

I'm finding it really hard to find any decent online resources, research and best practices around how websites deal with international audiences, i.e. the ability to serve the user the right content in terms of geography and language...

• Is there any research you know of regarding this?
• In your opinion, who does this really well? Amazon? MSN? Ebay? Google?
• What makes it a good experience?
• What are the pitfalls...what makes it a bad experience?

Would love to hear your thoughts on this...