Twitter Annotations represent structured metadata about the tweet. What that metadata contains is up to you. The feature simply provides a structure for how to specify the annotations and retrieve them along with the tweet.

Twitter Tools

SemanticTweet is a service constructing a RDF FOAF profile out of your Twitter account information.

The new release supports geonames. Which means if you put your geonames id in the "Location" field of your profile, such as at "Location geonames:6446645" it produces automagically at the following RDF ...

<foaf:Person rdf:about="">
<foaf:name>Bernard Vatant</foaf:name>
<foaf:based_near rdf:resource=""/>