The delivery of GIS technologies that are taking full advantage of the Web, and especially Web 2.0: georeferencing Sanborn maps of San Francisco, the NYPL map warper, and Harvard's WorldMap.
GIS and mapping is becoming such a big topic in the area of digital humanities because there is a geographic component to just about everything. And the tools are getting more and more developed for making new discoveries using old and new data, and connect them to a wide variety of people.