Public APIs for web portals like del.icio.us, "Google Office", Google Reader (references on the web but I have not seen it available yet), Flickr, etc. offer something special to computer scientists that are not available to computer users: the ability to "re-purpose" your own data and meta-data that happens to live on public web portals.
While there are very good systems like Piggy Bank for creating your own meta-data store (in RDF) for web sites that you visit, this requires extra work. The sweet-spot for automating the collection and use of our own meta-data and data is being able to automatically use information that you may already have for your own del.iciu.us tags, tags you have applied to RSS feed items in Google Reader, etc. Most of us use public web portals as part of our work flow, but there are definitely unexplored possibilities for customizing our own knowledge management environments.