Su2rad is an exporter for Radiance and DAYSIM for Google SketchUp written by Thomas Bleicher. The plug-in can be downloaded from http://code.google.com/p/su2rad/.
Su2ds is a Google SketchUp plug-in that's been developed by Josh Kjenner to facilitate the analysis of SketchUp geometry using DAYSIM. The plug-in allows users to specify all of the model information necessary to conduct a DAYSIM analysis and display the results of that analysis, all within SketchUp. It can be downloaded, for free at http://code.google.com/p/su2ds/. A small manual describing the plug-in's use can also be found at the above link.