Your personal IA pony

There's a great post on 43 Folders today called I Want a Pony: Snapshots of a Dream Productivity App. It's basically a personal information architecture wishlist--smart folders and cross-application, sharable, syncable tags and metadata. I liked it because it's not so much about a better app as much as a better way to organize, manage and retrieve the stuff we're already creating in other apps (as one commenter put it, "better glue").

Merlin articulates it nicely here:

I've gotten so used to thinking of an application as the entire locus of activity; what I really want are independent streams of structured information that can be intelligently munged at the device point--but with syncing of any flags, changes, and associations.

Lots of good ideas in the comments as well.