This is an assortment of recent papers by co-authors and me.
Click here for Part 1, 1.2Mb.
Click here for Part 2, 2.8Mb.
Click here for Part 3, 2.2Mb.
Click here for Part 4, 15.3Mb.
This paper is available on the IOP home page at http://stacks.iop.org/0266-5611/19/1113. It will appear in Inverse Problems, Volume 19, #5, pages 1113 - 1138.