These made an appearance in my bento pictured here [1].
grape or cherry tomatoes
fresh mozzarella sliced about 1/4" thick and cut to the same diameter as your tomatoes (I used stainless steel sakura shaped vegetable cutters [2] {note: I only linked to kaboodle because it came up in a google image search})
fresh basil
skewers (toothpicks work fine)
Cut tomatoes in half. Make a sandwich of all three ingredients! If you can use a part of the basil where two leaves grow opposite each other, they look like tiny space ships.
Variation: I used these as an appetizer at Thanksgiving, but in addition to using fresh basil leaves, I hollowed out one half of the tomatoes and spooned in some home made walnut pesto, which I got from Heidi Swanson in an article in Food and Wine [3].
Links:
[1] http://www.flickr.com/photos/34351188@N04/3208674370/
[2] http://www.kaboodle.com/reviews/flower-shape-vegetable-cutters
[3] http://www.foodandwine.com/recipes/broken-lasagna-with-walnut-pesto