Oh my goodness, me too.
Anyhow. For a destination wedding they say 9-12 months in advance. Our wedding is October 28th of next year and we haven't sent ours out yet. Not because we don't want to, just because we want to add some extra events and I'd like them to be on our website when we send out our save the dates so the guests can reference them.
The sooner the better is the consensus that I have heard when it comes to save-the-dates. With invitations it is 2-3 months in advance, but that seems a little close to me.