The owner of the store I work at is 74 today. He's pretty much turned over running the store to his son but he still comes in every day and takes care of the produce department. Whenever I have a question or a problem I usually go to him first. Sometimes it's just to see if I'm overreacting to something or not but 9 times out of 10 he agrees with my opinion.
No one had started passing around a birthday card yet for him so I took in one that I had made for everyone to sign. Nothing fancy but I don't think he'll mind.