An enterprising developer has wrapped the AdWords API in PHP, and is selling the library. Ostensibly it should make using the Google AdWords API a lot easier. Is it worth it? Oddly enough, I think PHP is one of the few languages where it's already easy enough to use the Google API.
A library for VB might be useful, however. Microsoft has made all the modern SOAP tools work well for VB.NET. Unfortunately, 80% of the world still uses Visual Basic 6 - and it's much harder to get VB6 to work with the Google AdWords API.
The easiest way to go? JavaScript and XMLHttpRequest! And that combo works well with Yahoo's and Overture's APIs as well. The low road works best.