Well, I've lived in NH, CT, NY, PA, DC, MD, VA, and driven north to Maine, south to Florida and west as far as Wyoming, but I don't ever recall seeing 85 for sale.

Ethanol is currently a small percentage of US gasoline consumption. But Monsanto and others are working on higher yielding strains, while the new ethanol plants (powered by animal dung) are achieving very positive energy returns (3 to 1 being conservative). Farmers are happy with $4 corn, but many suspect it won't last. Too much is being planted. Meanwhile, new farm equipment is more fuel-efficient than old. Corn was at this price in 1980, but tumbled (and that is before adjusting for inflation).
Looking ahead a generation, even with corn (not the best crop) we will see very positive and increasing energy returns. Remember, it was an infant industry, and is getting better at what it does. Combined with PHEVs, we can anticipate radical reductions in fossil crude demand out 10 years.
Interestingly, US demand for fossil crude is already dropping, according to the EIA. We used less, not more, oil in 2006 than 2005. And the real energy-saving technologies are just coming to the fore now or in next five years.
World consumption of crude rose 3.1 percent in 2004, then 1.8 percent in 2005, then 0.9 percent in 2006. I sense a pattern here. It is not as dramatic as the declines following the price spike of 1979, but then thse declines may have more staying power.
In most industries, growth like this is called a "dud." In the hysterical nomenclature of modern-day reportage (fueled by hedge funds who went long, no doubt) this is called "runaway" growth.
A remarkable scenario, unexpected by most, may be unfolding; Peak Demand perhaps 10-30 years before we see Peak Oil, if this price regime can be maintained.
If the price regime can be maintained, it will be Fat City for oil barons: The average cost of bringing a barrel up (including sunk capital costs) is probably under $20. The worldwide marginal cost is well under $10. The EIA said it was $3.57 a barrel in 2003.
If you believe that this price regime can hold, then buy oil stocks. Sell your house, sell your jewels, sell your booty, go deep into hock. It will mark an era of profits the world has never seen, for oil kings. You can also play options on the NYMEX. You will get very, very rich, while everyone else grows very, very poor. You will have gorgeous maidens doing your bidding. All for just seeing what the investing public cannot see. You have your hands on the gold nearly now!
The sad part is, I doubt this price regime can hold. Demand is falling across the developed world, and even further declines are being mandated and institutionalized worldwide.
Fat City is nearly always just out of reach. But if you really, really believe....

87 in Illinois and Wisconsin, and as far as I can recall from my occasional travels, in Indiana, Michigan, and Ohio, though it's not something I've paid close attention to. I had no idea 85 existed.

Note that in Europe the octane number on the pump is RON and not AKI (=(RON+MON)/2).