Thanks David! Your description is exactly what I hoped for: a simple icon (x2), single click operation with the cloned activity appearing directly below the original (minus user data). Thus if a teacher needs to clone the activity with user data, they should use backup/restore (tedious but that case would be rare I believe). All in all, a great addition for Moodle 2.1.
This plan will replace one of three functions of the Sharing Cart, which I still hope you can include in standard Moodle 2.2 code or later. The other two functions are: 1) moving a cloned activity from course to course in an easy way for teachers and 2) maintaining/organizing a library of frequently used activities to add into any course. These are essentially for our teachers--most used tool in our faculty who average 5-10 similar courses and are constantly cloning/moving activities. Therefore, our university is continuing to create Sharing Cart 2.0 and Project Course Format 2.0, hoping to offer them in May. The coding of course won't be up to Moodle HQ standards, but hopefully with us doing a functional one, this will save you time incorporating into standard code. (vote for CONTRIB 907)