1. A system for linking together digital information objects of a publically-available digital information space comprising: at least one locally-stored software artifact overlay maintained (i) on a computer comprising a web browser and (ii) separate from the publically available digital information space, wherein, at least a portion of the at least one locally-stored software artifact overlay is passed to a digitally-readable agent for information processing; at least one digitally-readable concept node within each overlay, each digitally-readable concept node expressing one concept, each concept defined by at least one keyword; and at least one digitally-readable information node within each overlay, each digitally-readable information node representing one of the digital information objects; wherein a link between an accessed digital information object in the digital information space and each of the at least one digitally-readable concept node is automatically established when the accessed digital information object and the overlay include at least one common concept, the link being omitted absent at least one common concept; and wherein Boolean logic modifiers are used to associate the at least one keyword with each concept.