I'm graduating college this week, and today is my last day of work at my student employment job. I've already done the standard letter announcing my termination date, but I wrote a thank-you letter to the director of the department too. I ordinarily wouldn't write something like this, but the director has written a couple of letters of reference for me over the past four years and one of them was for the job I'm moving onto after graduation. Should I just hand him the letter at the end of the day, or should I give it to him right now, even though I've got the whole workday left? EDIT: the letter's not just "thanks for the recommendations," it's about how much I've liked working in this department and how the skills I've learned here will be useful at my new job.