A single-user application that recognizes different entity types and connections among them. And can then make that data available to other applications running on the DeskTop our out on the net. Semantic Web, RDF.
see 2003-05-09-DecentralizationNotes - I'm starting to feel like the eventual model needs to be that each person has a single core/central app/Data Store ("Semantic Client"?) which then serves as a source for new (Social Software and other) applications. OSAF/Chandler, Personal Knowledge Management, EMail Address Book (for White List spam blocking), Instant Messaging Buddy List, WebLog, WikiLog, RssAggregator subscriptions for Universal Inbox, FOAF, new-book notifications, local-event notifications...
So when someone comes up with a new potential application (like LinkedIn, Ryze), there's some process of mapping your schema to theirs, and maybe you add schema elements and data to your Semantic Client because they'll have a use for it. (So the client needs to be super-flexible.)
And my client can poll other people's clients to monitor data and take actions. So when a friend from the west coast (or a favorite author on a book-tour) plans a trip to NYC, my client notices it and lets me know, so I can nag them about having dinner (Stalker Net).
Yep. I reckon the Semantic Client (which will be essentially the same as a Semantic Server, only with a GUI) is the way we're headed. It's interesting that the Chandler folks have been talking of seeing at a platform. Spot on. Ideally this would stretch right down to the OS, but failing that it can be layered wherever you like, thanks to Java, Python etc.