The tradition of the Easter bonnet is not what it once was, although for some people, hats never went away. In the African-American community, for example, there is a strong tradition of wearing hats to church; in England ladies wear hats to weddings (and Ascot), and New York has the Easter parade. Despite their relative rarity--or more likely because of it--when people do wear hats, it tends to be very noticeable. Which is perhaps why more people don't feel comfortable wearing them. The topper Aretha Franklin wore to President Obama's inauguration inspired its own Facebook fan page and generated a lot of publicity and new business for the Detroit-based milliner who created it.
It's hard to just go out and buy a good hat. It seems like most mid-range department stores offer mainly tired, dowdy styles. Good hats tend to be expensive, which is another reason for their falling into disfavor--most people don't want to drop a wad for something they're not sure they have the nerve to wear. For many hat aficionados, a piece by madcap UK-based milliner Philip Treacy, known for his sculptural designs, would be the ultimate purchase--his clients range from Sarah Jessica Parker to the Duchess of Cornwall.
Several milliners ply their trade in Chicago, including Eia Radosavljevic, who instructs students in the art at the School of the Art Institute (unfortunately she doesn't have many images on her site right now, but you can find some on the Web) and Marjorie Marshall, whose work was featured in the Reader's 2007 fall fashion issue. I also like the look of Tonya Gross' designs. In addition, a couple local millinery societies occasionally hold teas and other events that are good excuses to buy and wear hats.
In her blog the Lazy Milliner, local writer and hat designer Mary Beth Klatt writes that she senses a revival of a certain kind of hat: the cloche, a style that was popular during the Roaring 20s--and its aftermath, the Great Depression.