That kinda reminds me of something I did in my previous job. I wrote software for an internal help desk, sitting near the same area as the rest of the help desk employees (60+ analysts). Almost once a week one or two would leave for new jobs, since the help desk was an entry-level job that hired new college graduates. Whenever this happend there would always be a small party, and a card would be circulated around the area for everone to sign. I ended up having a custom rubber stamp made with my signature and the phrase: "Goodbye and good luck!" above it. Whenever a person would bring a card by, I would rubber stamp it, even if it was a birthday or congratulations card. If they weren't leaving, I would just cross out the phrase above my sig.