Just discovered DBpedia. It's a promising attempt to represent a lot of data from Wikipedia as RDF. You can download the entire extraction as a 16GB file, but it also has a keyword search page. Being represented as RDF allows for very specific "semantic" queries. This shows a few example queries, such as how you would find a list of the official websites of companies with more than 50000 employees. You can even query "the cloud" remotely with any wrapper that can interface with its public API, such as this Python module.
