Travel 100 metres without being seen.
Put on a performance for a CCTV controller. You could improvise a short play, show off a dance routine or hold a full blown talent show.
Climb to the top of the world's highest places without leaving home.
Get a friend to help you and explore just by smell.
Go for a walk; bring back your favourite memory and then recreate it.
Collect 26 photos of the letters A-Z in different places.
Create a beat, song, and perhaps a tune about a place.
Put identical containers outside in different places when it's raining... does one fill more than the other?
Paint a stone red. Leave it somewhere and then come back at a later date to see if you can find it again.
Cut eyeholes in a newspaper and then secretly follow some friends.How long can you go without being seen?