Doh, you confound me:
The Möbius strip has only one side. The Klein bottle’s inside is its outside. These remind me of Gabriel’s Horn, which has infinite surface area, but finite volume. Wicked.
Now for some more well known goodies:
You know it, you love it, you remember the rabbits on the island. Yay, Fibonacci! Fibonacci number is the sum of the previous two. The number of spirals in a sunflower or a pinecone is a Fibonacci number.
And lastly, PHI PHI PHI!!!