Voting from abroad is always quite a challenge for Americans. I've lived nearly half my lifetime outside the United States and I've never quite figured out the exact rules for overseas voters.
Happily, I no longer have to because the Overseas Vote Foundation is here to help. They are a non-partisan, non-political organization that exists for the sole reason to help American living abroad vote in U.S. elections. On their website is all the information you need if you are an American citizen living temporarily or indefinitely abroad. There is even a wizard to guide you through the process to get registered and obtain a ballot for the 2012 elections.
And if that weren't enough they have also produced this video which up on the site and Youtube to guide you (many thanks to the person who posted the link on the SFN site).
There are at least 6 million of us and I firmly believe that the very best way to send a message to Washington that we exist and pay attention to homeland matters is to VOTE.
Perhaps this will wake a few of those politicians up to the power of the American diaspora. :-)