Granted the dogpile pages don't have very many links, but there's always a link to the individual engines too, so that doesn't bother me much -- and since my main intent with it is to show how very different search engines can be one from the other, it serves me well. I used to only show beginners only one search engine or the "search" button on the browser, but they seemed to get dependent on that single strategy and pretty soon the frustration set in. Since I started teaching with a meta-search engine in the introductory session, the frustration quotient has been lower. (I'm in a public library branch, and my students come back to use our machines a LOT.) Anything that saves me having to come back and spend fifteen more minutes explaining how to experiment with the search in the middle of the homework rush is a plus.