I have been told that this engagement will be happening before I head to the east coast next month to visit my family. So I know it is coming.
I am so not traditional and after being through a divorce I think getting engaged should be a mutual decision between two people, because it is a partnership that you both are excited to enter into. As opposed to the boy asks dad for girl's hand, then asks girl, etc. BF was ok with this, but still wants to have some element of surprise, so that is why know it is coming, but not the exact date/time/etc.
That said, I'd like to get him something to commemorate the day. I know watches are sometimes used for this purpose, but I got him a watch for his birthday last year. I was thinking of getting him a nice, stainless steel engraved compass which he would really love both because of his hobbies and the work that he does professionally.