LINQ to Amazon
Yes, you read that right. LINQ to Amazon.
"This example introduces Linq to Amazon, which allows querying Amazon for books using Linq! It uses Linq's extensibility to allow for language-integrated queries against a book catalog. The Linq query gets converted to REST URLs supported by Amazon's web services. These services return XML. The results are converted from XML to .NET objects using Linq to XML"
Wow. (erm, did someone say REST?)
Michael Champion has some more LINQ to XML in action coolness.