The del.icio.us linklogging system
lets people use labels called "tags" to describe the links they
capture. The rich collective dataset of tags and the links they're
associated to enables the construction of something resembling a topic map, with tags as topics and links as occurrences.
Now, del.icio.us uses the right-hand column of tag-specific pages to
list tags that are related to the current tag. The details of how
relatedness is computed are not entirely clear,
but it is probably derived from tag co-occurence in individual
bookmarks. Browsing the tag landscape by clicking around tag-specific
pages is interesting, but how much more fun would it be to be able to navigate a graphical, two-dimensional map of tags, à la musicplasma or audioscrobbler browser? In that spirit, here is
Challenge number two: build a visual interface for mapping out tags in del.icio.us
Let the user specify a starting tag, get the related tags, and grow it
from there as the user double-clicks other tags in the map. There isn't
an API method for fetching related tags from del.icio.us yet, so this requires page scraping for now. Relatedness is not symmetric, but just assuming the links are two-way should do.
Let users visit actual tag pages by simply clicking on a tag. For bonus points, show the newest links or the top links in an info box when one clicks a particular tag.
