how about some added bs line to zoney's letter like:
Despite four great years here at :insert orgs name here:, I have made a tough decision to move on. I will be relocating to :insert city in Quebec here: in :insert time period here: and will miss the great working atmosphere here at rgs name:. The skills and knowledge that have been obtained here at [insert company name] are invaluable and will allow me to succeed in my future endeavors.
I wish rgs name: the best of luck in the future. I will only be a phone call away, and hope to hear from you.
Thanks again for four great years.
sincerly,
:Insert non-interference name here: