Did you know that the first Saturday of the month is free day at the High for Fulton County residents? This used to be limited to the first 100 guests but I don't think it is anymore (though I'm not sure). But you'll want to go early anyway because the museum is CROWDED on Saturdays. As I heard one guest say, "It's just like being in New York." If you don't live in Futon County or just like to pay for things, you can go on any Thursday afternoon, when admission is half price (regularly $18!) from 4-8 p.m.
If you go in the next couple of months, you will be able to see the awesome John Portman exhibit, featuring architecture, painting and sculpture. Portman, who graduated from Georgia Tech with a degree in architecture in 1950, designed many of the great buildings downtown, include the Westin, Hyatt, Mariott Marquis, and AmericasMart buildings. The High's website has information on a walking tour of Portman's downtown Atlanta buildings.
Also worth viewing is the installation "Altered Environments;" pieces from the High's collection that feature environments that have been altered by the artist or by people in general.