Semantic Markup and AutoLink

RSS/Atom is the proof that, given the right incentive, people/systems can be developed to publish semantically marked-up content. Building the semantic web, however, seems to have fractured into two; build it using the correct technologies (RDF + OWL) or bootstrap it by encouraging people to semantically mark-up some of their content. Jon Udell, as far as I understand the argument, has been consistent and imaginative in his support of the latter. He has suggested that what is needed is some mechanism to reward those people that go through the pain of marking-up their content. I just wonder whether an appropriately implemented 'AutoLink' capability could do that?

The need for an 'appropriate' implementation is, in part, a response to the furore that has arisen from Google's toolbar (e.g. Dave Winer's Google's toolbar and content modification). IMHO this isn't a question of whether the reader is prepared to accept having the content they are reading modified, it's a question of whether the author is prepared to allow their content to be modified. One approach is to have authors explicitly opt-in by marking-up content that can be 'auto-linked'. For example:

 
<p>This is a small post that contains an address. 
I found the address on Google's web-site:</p>

<ul>
Google Inc.
<span class="autolink" type="address">
1600 Amphitheatre Parkway
Mountain View, CA 94043
</span>
USA
</ul>

(taken from Testing Google's AutoLink)

To quote Jon Udell's The Social Life of XML, this uses CSS to smuggle in the metadata. Explicitly marking-up the content to be auto-linked and giving it a 'type' has the desirable consequence that the author is adding some semantic content. The explicit 'type' attribute also has the significant advantage that the approach is extensible beyond the point where Google's magic is able to identify a context. For example films, books and companies could all be identified by name.

Adding new types of auto-link could be reduced to the code required to manipulate the marked-up content into a suitable query string and the URL of an appropriate 'helper' service. Nor would it be anymore difficult to add support for alternate 'helper' services for the same type of auto-link (as Google already does for mapping street addresses). Of course having services work more or less directly with the sort of content that an author has access to is the genius of the whole thing. For example street addresses are a lot easier to come by than lat/long coordinates.