That was easy ;-).
The Luna Ambigram shown here is a nice short symmetric ambigram that is an engineered optical illusion at work.
As you can see from the preview, you can read this as 'Luna' when the design is upright and also as 'Luna' when the design is inverted (or is it the other way around?).
Simply mouse over the design to see it rotate.
Would you like to see other options? See an entire gallery of choices by clicking the Create New Design button.
Select This Design Create New Design