Well, it's finally official, Yahoo released the search APIs to the public. The [http://developer.yahoo.net/|Developer Network] has all sort of documentation, and downloads of example code and APIs. Obviously, you should use Python. Swaroop has already begun hacking, writing a [http://www.swaroopch.info/archives/2005/03/01/yahoo-search-p...|QT Image search] tool thingie. The Python APIs are hosted on SourceForge, at http://pysearch.sf.net/ .
I'm about 50% done with my next search project, a Gimp plugin that lets me search for Images, preview the thumbnail, and then import the selected image(s) as layers into the Gimp. I'll post with screenshots once it's looking less gimpy.