The other day I shared a pattern for a wine cozy, which is just one example of the greatness of having a gift that comes inside another gift.
I think it would be a lot of fun to knit up a little bag and put something fun inside that would allow the recipient to use what's inside and to keep that or something else inside the bag.
I have two great options for this sort of thing: the Handspun Bag and the Beaded Bag. They're both variations on the drawstring pouch, one worked completely in the round from the bottom up and embellished with beads, the other starting from a square from which you pick up stitches to work the body of the bag in the round.
I'm loving the idea of giving one of these to a child to put his or her treasures in, or to give to a doll to store her extra clothes in. Accessories are always fun, whatever your age!