This evening, api.google.com was removed from Google's DNS which made me panic a little bit (our keyword tracker and search engine script which are both based on the Google API have many thousands of users).
So I did a little poking around, and realized that if you use www.google.com for the API queries, it works now. So apparently Google did some shuffling.
Maybe it means the Google API is finally coming out of beta... or maybe it just means there are no longer any specific servers for the Google API (which would be nice, since the API servers are not as stable as Google's main servers).
Update: The api.google.com was inserted back into the Google name servers, but API queries to www.google.com continue to work.