I've heard the discussion about byond integrating with facebook, but that it might be too 'spammy'.

I, however, have an idea. What if the byond integration only posted to your wall when you earned medals?

That would be far less spammy. The only spam would come from games that barrage you with medals left and right, which are very rare, and very seldom played.
BYOND doesn't have that many medals to beat FarmVille spam, I wouldn't worry about that. Also Facebook started merging similar posts from same application, so it'll block too many posts.
Also, think about some evildoer with a game that would award somebody hundreds of pointless medals?
In response to OrangeWeapons
There could be some kind of link on the website that the players would have to click to publish the medal to facebook