My 7th grade English teacher, Mr. Dion, assigned us the task of writing a letter to our future selves to be opened at some date we had to pick. We even had to address the envelope and put a stamp on it. As I recall, first class postage for a letter was 13 cents at that time. I remember some of the details in it (mostly about a certain boy in my class who I thought was particularly sweet), but not much else.
I think I opened it around my high school graduation. In the intervening time, it prompted me to use the letter-writing technique as a sort of diary. I put the letters into a photo album, which I believe is stored in a foot locker that I haven't opened since 1991.
Now, there are websites that allow you to do the electronic equivalent of Mr. Dion's project. I just read an article about FutureMe and went there to check it out. I had fun looking through some of the public entries. One by a 14-year old boy to his 24-year old self was funny. Maybe I'll write one or two of my own. Will you?