Art can exist in many places besides a museum.
Art is more than just something to look at on a museum wall, and you don't have to be a professional artist to take part in it. There are all kinds of activities involving art that anyone can do. Many people associate art and crafts with children, but there is no reason that adults can't be creative as well.
Museum Sketching
Sketching in museums has traditionally been a way for artists to learn from and emulate their predecessors. Whether you consider yourself an artist or not, there's nothing to stop you from heading to the nearest museum with sketching paper and a pencil. Learn to see works of art in a new and deeper way by translating them into your own creation on paper.
Guessing Games
Using a collection of postcards or other images of famous works of art, play a game where everyone tries to guess the work of art and the artist. You can make the images easier or harder depending on the level of knowledge of the players. For kids, use very famous or easily known works and artists. For a group of art historians, use obscure images and make the game harder by asking for dates and other information.
Guerrilla Art
Make and leave art in unexpected places without letting anyone know who did it. This activity can take any number of forms. Build a sculpture in a public park. Sneak one of your works into a museum and hang it on a wall. Put up posters in a public bathroom. By appearing in unexpected places with no explanation offered, guerrilla art helps to make people more aware of art and makes them question what it is, thus engaging them in a deeper way than if they simply encountered it in a museum. Be sure that what you're doing doesn't break any laws.
Art Show
Invite friends and family to create something and hold your own art show. Take the right to make art back from "official" artists and museums. The caliber of the art may not be as good, but that doesn't matter. Making people aware that they have the ability and the right to make art is a worthwhile thing, and friends and family will be impressed with the latent creativity that exists in others.