1) An autism support ribbon.
2) All of my Mario games. (Or, if that counts as way more than one item, then just Super Mario World.)
3) A Waenya doll and a printout of the backwards lyrics to Never Want to Say it's Love by Dido. (Or, if that counts as two items, then just the lyrics, possibly for a different backwards song. Also note that I haven't actually manufactured a Waenya doll, but I probably would if I wanted to build a time capsule.)