airplane
"To shift the metaphor a bit, an airplane is like a goldfish swimming through a bowl being carried by a running man."
"An airplane is like a plant cell because it contains many differenet parts that make it work just like a cell."
They are both complicated systems; planes are man-made systems and cells arose from nature.
"Son, an airplane is like a woman. If you rough handle her, she'll kill ya. Treat her with respect and she'll take care of you for the rest of your life."
METAMIA is a free database of analogy and metaphor. Anyone can contribute or search. The subject matter can be anything. Science is popular, but poetry is encouraged. The goal is to integrate our fluid muses with the stark literalism of a relational database. Metamia is like a girdle for your muses, a cognitive girdle.