This would probably work with ResourceDescriptionFramework, i.e. the information would be a link to an exterior site (I won't really get into rdf and talk about URI's and suchlike, I'll probably get it wrong).
So one person would describe an opinion ("the war in Iraq was unjust", "the United Kingdom should join the monetary union", "God created the world in 6 days", "Microsoft sucks" ... ), and other persons can express their adherence to this by a link to that statement.
Before this leads to having 8000 links to cover opinions on a lot of minor subjects, you could probably get commbined opinions (an opinion that links to a package of other opinions ("the teachings of the catholics church, ie (link1, link2 ...).
Actually this could cover many more attributes than simply opinions, tastes and knowledge. It can cover any attribute, belonging to a group, etc.
Maybe linking to an opinion can be seen as signing a petition, or as voting. But VotingIsEvil.
As an additional feature, one could also add his degree of adherence to an idea/opinion/meme ... you could differenciate between Ideas you feel strongly about, those you feel pretty sure but are not interested in, those you would like to discuss, those you aren't sure and about which you might change your mind ...
Thus it would allow you so search for people who share your opinions on many subjects. Maybe you would like to see "the other side" on an issue and find somebody who has close opinions on most things but not on that issue. It would also be possible to look at global trends ...
(hey maybe I should replace "opinion" by meme here, thus increasing the buzword rate of this page - it is more or less expliciting memes I'm talking about here ...)
CategorySocialSoftware, CategoryWebLog