http://www.bp.com

I was waiting for this, so I got there first. Ahem. Here's my superficial analysis:

The world R/P ratio = 40.5 years. That's how long the world's proven reserves can reasonably be expected to last at the current production rate. However both reserves and production rate changes with time. From the early 1980s onwards, the following trend equations may be seen:

Production trend (starting 1983): y = 0.3746(t-1983) + 20.371 [billion barrels per year(y) produced in year(t)]

Reserves trend (starting 1980): y = 21.044t - 40948 [billion barrels reserves(y) in year(t)]

=============================

The trends show no obvious pattern of oil depletion (the R/P ratio will tend to increase with time!), except of course that we are burning lots and lots of it, and we don't think it's renewable. The only other pattern I found is that production has almost perfectly matched consumption for the last 40 years, and both are steadily increasing, following the above equation roughly for the last 20 years. So even though the current world R/P ratio is 40.5 years, the math suggests that this will actually increase with time, and the world's oil reserves will last forever. Common sense says something else, but the numbers clearly say "DON'T PANIC". Sometime this year the R/P ratio will be 42.