In beta, of course and as mentioned before, the Google AdWords API is now available. I did not mention earlier, that Overture has an API, not sure if its free. This opens up a lot of possibilities for the tech savvy PPC advertiser. There are several blogs covering this, including; AdWords API Blog, Google Blog, Search Engine Watch, Search Engine Lowdown, BattelleMedia, Traffick, SEO Book, Search Engine Blog, ThreadWatch, Inside Google, and Yahoo! News.
Forum coverage at: - Google Groups Official AdWords API Forum - Search Engine Watch - WebmasterWorld - HighRankings