[OCC] - It is a cool message though. I don't want to decode it and spoil it for people. :)

One thing about Base 64... I would not of thought to use that... you see Base 64 could be made up with different digits at the end. I made up one back in 1992 or 93 that was 0-9,A-Z,a-z,+,- which those last two digits are different. It was only a few years later that I realized something already existed that did it called MIME encoding. I suspect that is the same scheme used by you and Google there.

EDIT: Clarification - I did decode it... thought about posting the translation for people then decided to leave it a message... especially since you linked to a tool that can decode it.