It has applications in Economics, Biology, Pharmaceuticals, and is rooted in State Space Modeling, which with Kalman Filtering (paper, breakdown [warning: long]) was used in the Apollo program. Dynamic Linear Models are gaining in popularity. There exists an R package, and both a short doc and a really great (read: worth buying) book (sorry, not a download, but here's chapter 2) by Giovanni Petris, Sonia Petrone, and Patrizia Campagnoli with its own little website.
Back to the Land — an illustrated essay about giving thanks and food and joy and life and things to ponder and such by Maira Kalman. [more inside]
Maira Kalman does it again, with a beautifully illustrated blog post about her visit to Mr. Jefferson's Monticello. [more inside]