http://www.ietf.org/mail-archive/web/ietf/current/msg80472.htmlProminently mentioned inhttp://lesswrong.com/lw/w8/engelbart_insufficiently_recursive/
You might need a mousepad, your table surface might not be ideal.
http://www.ietf.org/mail-archive/web/ietf/current/msg80472.html
Prominently mentioned in
http://lesswrong.com/lw/w8/engelbart_insufficiently_recursive/