I participated in a two-part exhibition in January-March 2011, An Exchange with Sol LeWitt. It was a very personally meaningful show, since I regard some of LeWitt's work to be the greatest that the 20th century had to offer. The work was an unreleased, documentation/proposal drawing for the light/laser work, The Reddest Shift [...diagonal masters], 2010.
The catalog for the exhibition was just released and the print version is on sale here. You can also download an electronic (.pdf) version here for free.
For more on the legendary Sol LeWitt go here.