@gaieus said:
I don't know what help gives that suggestion (maybe that's for the Mac). Use the Ctrl key to modify the Move (or Rotate) tool to not only move (rotate) but also leave the original in place (i.e. "Move-copy" or "Rotate-copy") on Windows.
Thanks, right after I posted, I finally noticed the context-sensitive key suggestions bottom left and noticed the Ctrl key hint.
This is the quote from the offical Help page at http://sketchup.google.com/support/bin/answer.py?answer=94866
"Making copies. As mentioned previously, the Move tool can be used to make copies of entities within your model. To make copies of an entity using the move tool:
Select the Select tool (). The cursor will change to an arrow.
Select the entities to be copied.
Select the Move tool (). The cursor will change to a four-way arrow.
Press and release the Command (Microsoft Windows) or Option (Mac OS X) key on your keyboard. The cursor will change to a four-way arrow with a plus sign. This action informs Sketchup that you want to duplicate the selected entities."