Wow, this is incredible! I can only imagine how useful something like this will be when applied to complex architectural diagramming, or visualizing urban networks, etc. And open source too! Wow.
I've been toying around with this in an effort to map student enrollement across multiple campus, and associate the data with the department their degrees are in each program. Unfortunetly, I don't know how to build the correct type of data table for import that gephi needs. I'm working on it though! It's definetly cool to play around with regardless.