In the United Kingdom, new drivers are required to fix an "L-plate" to their car to indicate that they are learners: http://en.wikipedia.org/wiki/L-plate
In this cafepress shop, the same idea has been applied to children’s clothing for toddlers learning to walk, those learning to cook, etc. Please take a look!
I wonder if there’s an equivalent in the US? Anyone know of anything similar? Post it in the comments!