2. From Crude oil to more refined products
What products and materials are derived from crude oil ?
In what products are they used ?
And further on is there any idea how big there influence is in our world ?
First things first. After some looking up, because its been a long time since school, a primary overview of base products derived form crude oil is the following:

Refinery gas => Bottled gas, fuels
Petrol => Fuel for cars
Naptha => Raw material for chemicals and plastics.
Kerosine => Fuel for Airplanes
Diesel => Fuel for cars and lorries
Oils => Fuel for Power Stations, Lubricants and grease Hot crude »
Bitumen => Road surfacing.
[source http://www.moorlandschool.co.uk/earth/oilrefinery.htm]

This gives a crude idea of what the base products are and already some indications of what the economic and therefore also social consequences would be of dwindling resources. From this view, it can be seen that most of the devices we use for motorized transport e.g. airplanes, cars, lories, boats,... and even house warming, anything that uses the fuels, would be affected. This is the part we are most made aware of. And for further information I refer to other text. See text lists at the end. (1)

Also can be seen form this short list, that other products e.g. chemicals and plastics, road surfacing lubricants and grease hot crude would be affected. Perhaps Bitumen used for road surfacing would be less affected for a while as less easy accessible stocks could be used for the creation of that, or perhaps a new technique could be devised that reuses old road surfaces ?

The question remains, firstly what products(2) are fabricated from the non fuel derivates, and secondly, where fore and most importantly how extensively are they used in our economy. A quick look around learns that cd-cases, CD's, DVD's, DVD-cases, casings of monitors, pc, boxes, floppy's, minidisk, toothbrushes, my brills glasses, lamp parts, lamps, gsm parts, water bottles, racks, camera devices, camera films, paints, clothes all have products in them that originate in crude oil. I would be surprised if this would be all. This is just a quick look around my room, but many more products do exist, more than i'm currently aware of.

A further search on the internet found the following: The list is endless. Oil products fuel our planes, trains, cars, trucks, buses, and motorcycles. Oil also is used to heat homes. Chemicals made from oil are used to make products that range from makeup, toys, fabrics, sneakers and football helmets to aspirin, toothpaste, deodorant, clothes, hair dryers and lipstick to name just a few. Plastics made from oil are widely used in everything from compact discs and video cassette recorders to computers, TVs, and telephones. (3)
The reason e.g. plastics and other derivates are so extensively used is that they are very useful. This also means that they have a wide influence on our economies, and that certain things would just not be possible without there existence or would exist but not on the scale we in the west have become used to.