David Gleich is doing some interesting work; in particular, see his Personalized PageRank paper.

In this paper we investigate the use of Semidefinite Programming (SDP) optimization for high dimensional data layout and graph visualization. We developed a set of interactive visualization tools and used them on music artist ratings data from Yahoo!. The computed layout preserves a natural grouping of the artists and provides visual assistance for browsing large music collections.

Check out the visualization.

Also of interest is this talk on Numerical Linear Algebra for Data and Link Analysis.