My DH left last week for Afghanistan, so we surprised him several weeks ago with a "fake" Father's Day. We picked a day and just pretended it was Father's day. We tease my DH that he is very much like Clark Griswold in that he would be perfectly happy driving 2 hours to see the world's largest rocking chair or something.
He has been talking about a train ride and the normally the kids and I roll our eyes, but for Father's Day, we got tickets to ride the Royal Gorge Railway with a promise that there would be not one complaint on the entire trip. It is important to note that the no complaining was actually part of the gifts.
We also got a few things to take with him on his deployment. History DVDs and talking picture frames with their pics from the kids.