Here's an idea that would have horrified the urbanists of the 1960s: More billboards. Especially downtown.
The idea probably horrifies some urbanists today. Billboards have been regarded as blight for more than 50 years. Often considered crass and commercial, they're thought to detract from the streetscape, and add nothing but a blaring command to buy, to drink, to eat. Surely the streets are better without them.
Yes and no.
It's not as if they're completely gone. You still see them around town, where they are legally permitted. And you might not give them much thought, because most billboards today are visually uninteresting. They seem to be apologizing for being there in the first place. But there was a time when the art of the billboard was remarkably lively — fun, bright, vivacious, artistic.
People who remember nothing but boring cigarette billboards might be surprised to see some examples of the art at its height. In fact, there were billboards and signs you'd drive out of your way to see. Some even became landmarks.
Remember the Ewald Bros. cow billboard by the State Fairgrounds, or the huge electrified Golden Guernsey sign that once stood atop the Rainbow Cafe building at Lake and Hennepin? Even the average sign might be a pleasure to see, if it had an alluring illustration or an amusing tableau, like the Ohleen Milk ad, which showed a diapered baby with the words "Time for a change." Not sophisticated, perhaps, but it could make you chuckle.

What happened to billboards? Laws and progress.
There was a big wad of legislation called the Highway Beautification Act of 1965, pushed by Lady Bird Johnson, as LBJ's wife was known. Some of the provisions were uncontroversial, such as putting screens up around junk yards, and picking up litter. But the bill also sought to reduce the number of billboards on highways, because some people thought they interfered with the endless green serenity of a highway drive.