Second Grade Pen Pals, anyone?

Is writing friendly letters as part of your second grade curriculum? Are you interested in writing friendly letters back and forth throughout the year? We average around 20-23 students per class at my school. I am interested in pen pals. Maybe if we wrote to one another once each month, it would be feasible. Has anyone else done this? How did it work out? Is anyone interested? Comments and ideas, please!  :)