Well when I started this thread, it was at the time where oil prices were skyrocketing and it seemed that oil supplies had hit their peak and now demand will always be increasing faster than supplies can become available. If the US were not in a depression right now, the price of oil would keep skyrocketing and only become more scarce.
The US has oil reserves it isn't tapping into, but regulations keep those wells from being exploited. The most recent issues have been the hurricane Ike damage, but gasoline prices have fallen as a result of the depression. Prices don't directly correlate to how much oil is still underground, but the amount of tapped sources are drying up more quickly than new pumps are established.
The best solution? There is no one solution that works for everyone. The best universal means to deal with scarce resources is to reduce the demand before anything else is done. It is the simplest way because it can be done today. Any new oil wells drilled today would start returning on their investment years later.
The better option to more efficient cars is the use of mass transit... then that requires overcoming another set of challenges.