Speculators, fueled by the tumbling dollar, have driven a barrel of oil above $90 for the first time. For light, sweet crude — the low-sulfur grade refined into gasoline — the price in after-hours trading hit $90.02 for supplies delivered next month. That came on top of a $2.07 rise during regular trading on the New York Mercantile Exchange, where crude closed at $89.47.

"There's still no end in sight in terms of what people are willing to pay,'' Bob Frye, a commodities broker at Access Futures & Options Trading, told Bloomberg. He added that if the dollar's weakness against the euro continues, the price could hit $96 a barrel.

Update at 7 p.m. ET: Energy experts are in Houston this week to debate "peak oil" — the idea that production will hit a peak in the near future and then decline irreversibly. New research being presented indicates that the impacts of peak oil might hit sooner and harder than previously estimated.

Here are reports from the Voice of America, the Houston Business Journal and The Oil Drum, along with background on the conference from the industry's Oil Online. In a variation on the theme, the blog earthfamilyalpha frames the issue as "plateau oil," when production and demand are flat.