In my case, I distribute my source code (greasemonkey javascript, no
compiled code...) with the key inside under GPL, this is probably not
the best way of doing it as anyone would have the right (under GPL) to
reuse the key to do whatever they want with it.
You could use a "less open" license like cc by-nc-sa which would
forgive anyone to use your key for commercial uses which is one of the
conditions to get the key from upcoming I think...
Another solution is to put the key in a separate file with its own
";closed" license that no one can reuse.
People could read the key and reuse it, but they'll go against the
license and if you really had problems from their use of it, then you
would have legal grounds to protect you (I guess...).
Pierre
.