I am sure you have seen Ace's projections that show based on a field by field analysis of what companies are saying about when new fields are coming on line. He also takes into account expected decline rates of existing fields. Ace's forecasts were higher before the financial crisis hit. Now that oil prices are lower, companies have pared back their plans for new projects.

The reason that even after the next few years a rebound is unlikely is that base production is dropping rapidly, because of the decline rate on existing fields. Once we fall behind in adding new production, it will be virtually impossible to catch up again.

We know many of the biggest fields, like Ghawar, are getting closer to the end of their life. Surprises on the downside are much more likely than on the upside.

We would really need some upsurge caused by low-priced improved technology to get more oil out. At this point, we don't see any signs of this being at hand. Most of the possibilities seem to be high priced, and will set the economy into a tailspin if oil prices are high enough to support them.

I have succesfully convinced some people, but some others are hard to convince.
One person replied: "I prefer to live in ignorance"
When trying to convince someone, ask him/her: why the oil companies have not invested in new refineries?
Tell people that in one TOD survey, 81% of the participants believe Peak Oil already happened, is happening now, or will happen before 2013.
http://www.theoildrum.com/node/5186
http://www.surveymonkey.com/sr.aspx?sm=Up5DUIASuWiOv4TyiyK6SBwfqHaAMra5q...
The following video is very convincing:
http://video.google.co.uk/videoplay?docid=-596805984521272213

And if a person does not have 33 minutes, ask him/her to watch these other videos:
http://www.youtube.com/watch?gl=GB&hl=en-GB&v=xT-ZpYgaHgc&feature=related
http://www.youtube.com/watch?gl=GB&hl=en-GB&v=l0MWDQ6JPTo&feature=related
http://uk.youtube.com/watch?v=xT-ZpYgaHgc&feature=related
http://uk.youtube.com/watch?v=l0MWDQ6JPTo&feature=related

Also, ask them to see the following OIL REPORT:
http://www.energywatchgroup.org/Reports.24+M5d637b1e38d.0.html

and to read this: http://www.energybulletin.net/primer

tonyp:

I'd like to convince some friends that 'peak oil' most likely took place in 2008. Of course I can give links to ASPO and other predictions but then they can say 'why should I believe that?

Don't rely your case on what people are asserting/predicting. The facts to date speak loudly enough (to those with functioning ears). Firstly in any productive engagement you have to lead them with questions rather than preach to them: "Are you envisaging to be alive in 5 years time?", "Where can you get sound information from?" (etc.) Flatter their delusion of being rational inquiring minds! (and respect them as equals who might surprise you by showing you to be in error yourself; why should you expect respect if you don't give it?)

Then just observe how (a) the production growth has stalled since 2004. Note how (b) the financial/credit/economic system is crucially dependent on continued growth. Note that the implication of (a) plus (b) is that some sort of economic crisis right now is inevitable, and is indeed taking place. Note the failure to invest in future production, due to faulty market. Producers squealing that they can no longer produce at the current prices. Exporter countries relentlessly turning into importers.
This isn't rocket science and it does not depend on blind faith in some incomprehensible 'ace' etc expertise. Rather it's the denial position that is the act of blind faith.

I'd like to convince some friends that 'peak oil' most likely took place in 2008.

Why?

I don't mean that rhetorically, either, but as an honest question: for what reason do you wish to convince them of this particular proposition?

If you want them to engage in a particular behaviour, such as consuming less oil, then directly addressing that behaviour is almost certainly a more productive approach. For example, simply noting that: (a) oil production seems to be struggling to keep up with oil consumption; (b) that led to high prices in the last few years; and (c) prices are still relatively high and likely to rise in the near future is much less controversial and uncertain, but should have much the same effect in terms of raising awareness regarding oil consumption.

By contrast, if you want to induce a particular mindset, such as believing that civilization is ending, then the timing of peak oil is only one tiny fragment of what you'll need to convince them of. In that case, you're not merely trying to convince people of a physical fact, but of your interpretation of that fact, which is a much harder task. Your interpretation likely relies on a hundred assumptions and leaps of logic you've made, and getting your friends to accept those may be no easy task.

So ask yourself whether you want to convince them of the idea that oil availability is permanently dropping, or of your particular beliefs about what that will mean for society. The first of those is pretty easy - show them a few graphs of prices and rig counts - but the latter is something that will be extremely difficult to provide an evidence-based argument for.