What is a gallery?

Art works and the books that helped the artist create them shown together.
On display now at Winkleman's Curatorial Research Lab.

Hiroshi Sugimoto
at Gagosian Gallery.
Half of the photos were shown in a pitch dark room with illuminated photos, half of the photos were shown in a light room, 'normal'.

James Luna's performance where he, a native american, was displayed in a history museum. Questioning differences between types of museums.

Consider also Fred Wilson and his curatorial process of mining a museum. Above are silver vessels and slave shackles from antebellum south both from one museum's collection displayed together. more here and here.

Mark Dion's installation in a public space, where he constructed a greenhouse, and uses a real dead tree, which becomes a home for other organisms, as his art piece and gallery. here

Also, consider artist Krzystztof Wodiczko, who makes large scale interactive projections in public spaces.

Neozoon's art using fur coats in public spaces. Can we equate a wall with an illegal tag on it to a gallery space?

It seems that with art expanding the space to show art expands. Good artists/curators/gallery owners recognize the type of art they want to create/show, and then figure out the best way in which to display it. Methods of display, as examined above, are becoming integral to the experience of the art itself and can no longer left only to the realm of Installation Art.

Unfortunately, complete artistic freedom is commonly only given to graffiti artists, which has obvious drawbacks. Hopefully more and more galleries and museums will continue to allow experimentation and expand what their gallery space can be.