A related question:
I just took on a website where the previous developer made every page an index.htm and created a separate directory for each page - /keyword/ naturally. This has a very spammy feel to me, but the search engine ranks are not too bad. There is a lot for me to do, however - the site hasn't been touched for nearly 3 years!
So the question - are directories containing just one page at a disdvantage? That is, is there a compelling reason to "flatten" the site a bit, or is it best to leave the structure as is, and therefore not be changing any of the URLs?