You know what I bet they just don't do in schools anymore because of how we've got the internet now? I bet they don't do penpals, the kind that teachers assign you to have.
I remember being involved in two penpal projects during grade school. The first was just between our class and a class of students that were a grade or two older than us in our same school. I was assigned a kind of tough kid who I would always see playing four square during lunch, so I sent him a letter that was like "My name is Brigham. I love playing four square." I really didn't have very passionate feelings about four square, but I thought it'd be good to appeal to his interests. I never got anything from him, I think the fact that he might not have known English is partially to blame for that. Also of note, the kid's dad (or legal guardian?) would pick him up from school in a truck that had a bumpersticker that said "Poker players do it on the table." I sort of got that joke.
My second teacher-appointed penpal was a girl that lived in St. Louis. She came on really strong by including a photo of herself in her first letter. Feeling low on inspiration, I sent her a letter telling her I was really into four square, and that was pretty much the end of that penpal project.
I never had one of those penpals that lived in Russia or Kenya. If you had one of those, I'm guessing you went to a really smug school.
I think now teachers just ask their students to add kids they've never heard of to their buddylists or something.