I think it sort of depends. For instance, I still live in the area I went to my undergrad and I see my letter writers frequently, so I'm giving them the thank you gifts sooner rather than later and then I'll tell them about results as they come up and as I see them. But if I lived further away and didn't have as much contact with them, I might send along the thank you notes when I could also let them know about results. If that makes sense...