...and call your dad if he's still around.
I wish my dad was here to spend Father's Day with, but he passed away in 1996. Not a day goes by that I don't think about him or miss him. When something exciting happens, there are still times that I'll start to think, "wait til I tell Dad!"
I have a wonderful father-in-law. But he's not my dad.
So if you have a dad or a step-dad in your life and you can't be with him today, call him up and let him know how much you love him!