By temporarily lifting the gas tax, demand would increase. Increased demand with a limited supply will raise prices. The price would likely bounce right back to where it would be with the gas tax, resulting in even higher profits for the oil companies. So people wouldn't see the savings they are hoping for and the government would lose out on the much needed tax revenue.

If there is no difference, then why not call them the same thing?

Unfortunately not everyone has the means to save for their own retirement so SS is necessary to provide for those people who would not be able to save on their own.

Wii is so much more fun for non gamers. And you can play a game in just a few minutes - Xbox games require a huge time investment.