The White House Says and The Government Says are two fantastic services put together by Sam Smith with help from MySociety and Democracy.org.uk. These enable you to search a vast mine of information that spews forth from governments.
Now the collective has launched spinDifferent.com, which makes it possible to compare what the leaderships of US and UK are saying on specific topics, as well as the United Nations. We can now look at these side-by-side and work out whether there are perhaps spooky patterns in the way they talk about WMD or terror. (On that latter point, a quick search reveals the recent banning of the phrase "War on Terror" by the UK government).
As Sam Smith points out, one advantage spinDifferent.com has is the ability to see where an issue stands on the governments' agenda. Search on Sudan, and you will see that the UN is a great deal more vexed about the situation than the US or UK.
Tools like this are only set to become more and more powerful. As some point I daresay we will even be able to graph key phrases and issues and work out how we are being spun by government.