I've just finished up a report on how Yahoo, MSN, and Ask are competing with Google in Europe. The short answer, of course, is that they're not competing very well: Google is incredibly dominant in all the key European markets. But there are some ways that the other engines can start to claw back some share, and our report -- which should be published in the next few weeks -- talks about some of the strategies that we think will work best.
One of the things I focused on in the report was the integration of specialty search (e.g., image or video search, directory search, shopping search, news search) into standards results pages -- what Google calls Universal Search, and what Ask implemented as part of their 3D search results pages. During my research I found a couple of good blog entries on the topic over at Ramblings About SEO. They did the kind of thing I like to do: they tracked each engines' response to a variety of search queries to see what types of multimedia content they're integrating into their results pages, and how far up the page these multimedia results appear. You can see the results of their image webtrack here, and the results of their video webtrack here.
Unfortunately there's not a lot of detail or analysis -- and nothing along the lines of best practices -- but the blog Inside Facebook has posted a useful list of every possible way companies can use Facebook for marketing. It'd make a good read for executives who want to understand the breadth of marketing opportunities on social networks, or anyone brainstorming a Facebook campaign.