Orphaned teacups make perfect little temporary pots for young myrtle trees that can then be used as gifts, party favors, or place settings.
Source: Martha Stewart Living, February 1997
Put a thin layer of gravel in each cup. Plant topiaries in potting soil, and cover the dirt's surface with moss.
Place near a window, and water when dry. After a week or so, transplant to a pot with a drainage hole.