objects to facts to links to LOD to ???

Hello Friends,


We have now reasonably good repository of linked data but i am not able to
find any good application being made out of it. From the dicsussion on these
mailing lists and other places, i got the feeling that everyone in semantic
world thinks that semantic web is something big but unfortunately nobody is
able to think of an application for _general public_ that can be based on
semantic web data we have currently.


This led me to wonder that are there any more layers of information
organization missing in the semantic web stack that are needed to generate
good usable semantic web data which can be more useful for generating useful
semantic apps . Few of the concepts i was thinking for upper layers to
implement were like categorization, set formation(eg MIT passout in 2002),
set intersection, etc. With these higher level layers I was hoping to build
a system to find higher level relations say between places with low cancer
rates and the food people eat there or any perticular gene found in such
people.


The current semantic stack looks like this:
.....
layer5 (???)
layer4 ( ???)
layer3 linked facts (isa(mars,planet) AND partof(mars,solarsystem) AND
mass(mars,6566.1255kg))
layer2 facts (isa(mars,planet), isa(cow,animal))
layer1 objects (eg cow, mars, man)



Are there any other thoughts on the need of layers above the layer 3 (linked
data ) or these layers will be defined by the respective apps developers ?
Even if there isn't any need, i would atleast like to have a discussion on
the kind upper level layers we might need :)


thanks
ravinder thakur