Semantic Maps has a subclass of SMWDataValue for the coordinates data type (which implements getDBKeys), and uses getDBKeys on instances of this class in the SMWValueDescription deriving class for coordinates.
I did a search through all extensions I have (which includes everything that's in the Semantic Bundle (and not including SM)), and only found SIO using getDBKeys, and nothing having a deriving class from SMWDataValue.
Jeroen De Dauw
Don't panic. Don't be evil.