Amazon.com has added a number of useful RSS feeds to their site.

The URLs are not exactly models of simplicity:

http://xml-na.amznxslt.com/onca/xml3?mode=electronics &bcm=Electronics%3A%20Software%3A%20All%20Software &t=webservices-20&dev-t=amznRss&type=lite&page=1 &ct=text/xml&sort=+salesrank &f=http://xml.amazon.com/xsl/xml-rss091.xsl &BrowseNodeSearch=229534

but it's good to see RSS becoming mainstream!