http://sketchup.google.com/download/previousplugins.html
http://groups.google.com/group/gis-and-sketchup/browse_thread/thread/c20798f42268811b/74b42049a23a70ee?pli=1
http://download.sketchup.com/OnlineDoc/gsu_win/K-Input_and_Output/Import_and_Export/IO-SHP-Import.htm
These were over in the 'Retired' Google Groups', their compatability with 7.1 is something i can't test as i don't use .shp
Maybe another member can help with this?