Euler's original publication in Latin on Graph Theory (The seven bridges of Königsberg) - http://www.math.dartmouth.edu/
The basis of all the latest hype around Facebook's Graph Search, Social Graphs, Knowledge Graphs, Interest Graphs etc., are the modern implementations of the above publication that formulates the Graph Theory in 1735.
I was fascinated about the Graph Theory during my college days and I feel it is one of the most natural structures how information is organized. A graph when used as a thinking tool of “mind map” is very effective as well.
The beauty of a Graph is its simplicity of being able to build and use it as a data structure to naturally traverse and split the graph / network into sub-graphs with ease. It is one of the best suited structures for massively parallel processed algorithms.
As the seven bridges of original paper were on the River Pregel, Google named the research project for large scale graph processing with the name. Let the programmers start thinking in the realm of vertices and edges….
What is offered by Pregel:
More on the Google's Pregel research paper - http://kowshik.github.com/
I expect in future quantum computing will build virtualized, software defined dynamic cliques of order 'n' as needed to solve the computing problem using graph algorithms with highest fault tolerance and highly parallel "just right" performance! Let me name it - "Goldilocks Computing". It is not far in the future...