My father-in-law was discussing the other day how much less useful Google has become lately. He's an electrical engineer; it used to be that, if he wanted to know about some part, he could just google it and find a spec sheet for what he wanted. Nowadays his answer is instead buried among huge numbers of sites trying to sell him the part or the information on it, and not providing the actual information.
I encountered the same phenomenon just now, trying to find online galleries of posters like the one from which my new icon's art comes. I found the poster itself in a book, Off the Wall: Psychadelic Rock Posters From San Francisco, by Amélie Gastaut and Jean-Pierre Criqui, which I picked up in the Gallery Bookshop in Mendocino, and it was not hard to find scanned images of it from various poster shops on the web. But when I realized that there must be online galleries similar to the collection in the book, and went looking for them, I found the search more difficult than expected; the obvious keywords like "psychadelic poster art" just led to commercial sites.
Eventually I found some sites by entering more specific information, the name of the artist (Bonnie MacLean) of the poster in question. Apparently online art exhibits care more about that kind of information than online memorabilia salesmen do. For future reference, the two sites I found are Pooter's Psychadelic Shack, and Professor Poster.
Google has had some success splitting out different kinds of searches: Google blog search separate from its main web page search, etc. I wonder whether a similar more specialized non-commerce search would be helpful? The question is how to distinguish the commercial sites from the other ones. It isn't the .com address (both of the real sites I found had that), and it's not even the actual information content (many of the commercial sites have fine poster collections), but how it's organized and the intent behind the organization; it seems difficult to determine that intent automatically. Alternatively, one could imagine that people who make lists of links to interesting art sites are more likely to list the noncommercial ones; I wonder how well Kleinberg's hub-and-authority model does at picking such sites out, relative to Google's more naive pagerank algorithm?
Something like a personalised version of mindset.research.yahoo.com and progress in faceted classification might eventually(!) take care of such results.
I've encountered similar frustrations. One of the best strategies I've come up with is the minus sign. For example, you might add -price or -order to your Google searches to exclude commercial pages. Maybe -visa would be more effective. New challenge: finding the optimal exclusionary keyword.
Yeah, I do that sometimes, but I don't think I've found the right negative keyword yet.