I can use shift to snap to 90 degree increments, but what about 45? Is it possible? I remember there was a plugin that let you do this but I can’t find it.
EDIT: Found it!
http://www.zbrushcentral.com/showthread.php?161588-quot-Axis-quot-Plugin-for-ZBrush-4r2
Go to the last page for the latest version.