AMBIGRAMS

The first one I remember designing was something like this, where the word "backward" looks the same when you hold it up to a mirror:

Here's another with mirror-sameness:

Of course, you can do the word "mirror" itself like this:

Rather than being the same in a mirror, this one reads the same if you turn it upside down:

I made a label for the honey bottle that reads correctly even when you turn it over while using it:

Here is the name OHIO, which is spelled correctly even when given a quarter turn:

I made this version of my business name, so it can be put on the window and look the same whether you are inside or out:

Some ambigrams say one thing when viewed one way and another when viewed upside down.
This design could be put on a magnet for the dishwasher and turned to indicate whether the dishes are clean or dirty:

OR

Click HERE for a tongue-in-cheek application of the same principle.

This was intended to be a prototype of a metal sculpture of my first name; when reflected in water with me posing so that the middle zigzags are obscured, my last name appears: