This may indeed be a close second to the dream of getting a 747 aircraft: MoMA has announced that it has acquired the @ symbol for its permanent collection. Here's from their blog:
Contemporary art, architecture, and design can take on unexpected manifestations, from digital codes to Internet addresses and sets of instructions that can be transmitted only by the artist. The process by which such unconventional works are selected and acquired for our collection can take surprising turns as well, as can the mode in which they're eventually appreciated by our audiences. While installations have for decades provided museums with interesting challenges involving acquisition, storage, reproducibility, authorship, maintenance, manufacture, context--even questions about the essence of a work of art in itself--MoMA curators have recently ventured further; a good example is the recent acquisition by the Department of Media and Performance Art of Tino Sehgal's performance Kiss.
The acquisition of @ takes one more step. It relies on the assumption that physical possession of an object as a requirement for an acquisition is no longer necessary, and therefore it sets curators free to tag the world and acknowledge things that "cannot be had"--because they are too big (buildings, Boeing 747's, satellites), or because they are in the air and belong to everybody and to no one, like the @--as art objects befitting MoMA's collection. The same criteria of quality, relevance, and overall excellence shared by all objects in MoMA's collection also apply to these entities.
There's a ton more to the post, including some fascinating history of the symbol. Read the whole piece here.