We did this last year... After much debate, I decided to take this picture of myself doing the "Buddy Christ" pose from Dogma, Autographed it "YOU'RE AWESOME!! Hugs and Gumdrops, Chris" and frame it with a $25 iTunes Gift Card hidden behind the picture... That way, when nobody fought for it, they would realize it was a better gift than it appeared... Turns out people did fight for it and it now sits in my Regional office where all the big wigs can see... FML... Anyway, if you know the people well, that may be a good gag...
EDIT: And if I had half a brain, I would have realized you only had 24 hours from the 18th... Sorry...