The Oil Drum

What do you suggest people do who live in Switzerland to prepare for PO (besides starting to plant a garden... :-).

It depends on your circumstances. Switzerland is a peoples of renters. The majority of the Swiss live in rented apartments rather than in private homes. Such people can do relatively little ... not even plant a garden, except possibly on their balconies.

If you are lucky (wealthy) enough to be a homeowner, you can do much more.

1. You can try to minimize your exposure to fossil fuels. Primarily, you may consider throwing your central oil heating system out and replacing it by a heat pump. You might consider going for a liquid-to-liquid heat pump that can be supported on the primary side by a geothermal system. You might also consider to support the system on the secondary side by solar collectors. The viaGialla website may help you figure out what you might need at the location where you are.
2. If you have an older car that you wish to trade anyway, you might consider getting a smaller (lighter) car that offers a better gas mileage. I wouldn't recommend to switch cars just for that purpose, because already in a year or two, you might be able to get a yet better deal, but if you are thinking about trading cars anyway, fuel efficiency should be taken into consideration.
3. The worst electricity consumers in any household are refrigerators and freezers. Most modern appliances here in Switzerland are optimized for low electricity consumption, but if you currently have a very old refrigerator and/or freezer in your home, you might consider trading it. The reduction in your electricity bill will pay for it after a reasonable amount of time.

These are items that often are worthwhile looking into, beside from low-energy light bulbs that everyone is talking about. Anything else (like replacing windows or improving insulation) needs to be analyzed carefully and requires an expert. I wouldn't do it, unless you plan to renovate your home anyway for other reasons.