Hello this is how you get Camtasia 6.0 lisenced for free.
First download the trial here
http://www.techsmith.com/download/camtasiatrial.aspWhen you download it when it says 30 Day Trial or Lisenced - I have the key, choose Licensed...
Then Type this in, License Name: Ethion00b
License Code: FSJMD-X5E5B-FN75C-B7N49-M9B33
Install it and it should be licensed and ready for you to use whenever you want!