In the late 1990s, when I lived in Oregon, it got as low as $0.87 per gallon. I had a '95 Escort that got 42 MPG on the highway, so I would fill up for under $10 and drove all over the Northwest. Good times.
The cheapest gas I've seen in Los Angeles lately was $3.83 in Westchester, near LMU. The highest is $4.07 and the average seems to be $3.99.
Someone earlier mentioned cheaper gas due to proximity to a refinery. Not so everywhere. Chevron has a large refinery in El Segundo with a station on the corner of their property. It is a fair assumption that costs to move gas several hundred feet are not that high. Yet this station often has the highest prices around. Strangely, the Chevron in downtown El Segundo, about a mile from the refinery, usually costs less. Go figure.
I don't mind the high prices so much. Not to light a fuse, but these prices have gotten plenty of SUVs off the road, made a lot of aggressive drivers take it down a notch and cleared out a lot of uninsured clunkers who just can't afford it. Also, the prices are making alternative transportation and fuels suddenly reasonable. That's a good thing. We didn't go back to whale oil after the light bulb, after all.