Among the presenters in the final stretch of the 2008 Demo conference were a pair of companies that are focused on search results geared specifically to the preferences, needs, and personality of the searcher. It was apparent that that's not necessarily such a great thing.

Delver is a "socially connected search engine" that provides results gleaned from people linked exclusively to the user via Facebook and MySpace friends list, plus an extended network of "friends of friends."

Searching on Vail, for instance, said Delver CEO Liad Agmon, might bring up other people from your social network who are into snowboarding. "Then you can call them up and say, 'Hey, want to come snowboarding in Vail?'"

Delver also will deliver results from blogs, Flickr photos, and the like, all in a hierarchy depending on the proximity of the source in the searcher's online social network.

Similarly, Circos, which bills itself as "a search engine with a brain and a heart," uses specific preference data from the searcher to refine search results and add "opinions from authoritative sources" that match the searcher's needs and desires.

Circos "understands who you are and what you're looking for, to guide you to the right options," said CEO and co-founder Morris Sim. "It takes me-centric search to a whole new level."

That's great, if what you're searching for is the right pair of shoes to go with that handbag you just bought. For broader types of searches, there are a couple of specific problems with these models, and one big overarching flaw.

First, Delver, obviously, only works for Facebook and MySpace users. There are millions of those, but not everyone searching on the Web falls into that category. Second, the "authoritative opinions" collected by Circos are culled from online reviews and blogs -- and anyone who has read online reviews and blogs knows that they are often authoritative only to the degree that the writer considers him- or herself an authority.

The larger problem I have with "me-centric search" is that, as often as not, that defeats the purpose of an online search. If I want to know what my friends and family think of the nightlife in Vail, I'll e-mail and ask them. If I search online, I want to move beyond the rather bounded perimeter of my social network and my awareness and find stuff I wouldn't otherwise know about or have access to.

For example, if I'm searching for information on the Riemann zeta function, I don't really care what my ex-girlfriend in Little Rock thinks about it, fond of her though I might still be. I want to expand my knowledge, not reinforce what I (or my pals) already know. For all its flaws, rare is the Google search that doesn't turn up something unexpected or lead off in unforeseen directions. The beauty of the Web is that it's an endlessly branching network of pathways through an infinite forest -- not an echo chamber.

Next up, continuing my Demo coverage, I'll tell you about a "contextual search engine" that has the potential to revolutionize the way we organize and structure online information.