There is a new group on OurCompassion that is inviting people to write letters to children in the program who don't yet have sponsors. You can write letters, send stickers, bookmarks, etc.
To find out more about this, join OurCompassion and sign up with the "Encouragement and Hope" group. They have all the info on where to send your letters.
My daughter and I made some cards/bookmarks to send. We'll put them in an envelope along with some stickers. I hope the kids like them!