I know that he will be pretty jetlagged, but I tried to do a few special things for him since he will be coming back to the apartment while I'm still at work. Many years ago, the husband made me a little "Happy Birthday" banner out of construction paper and thread. It was so sweet and thoughtful, so I wanted to do something similar. I cheated and printed the letters on paper and then cut them out. I think it's probably better that way though, because you can actually read the sentiment.
Treat.com. They were running a sale last week where all the cards were 99 cents, and I definitely stocked up. I really love how you can personalize your message.