Last night in Los Angeles, Tesla Motors unveiled their fast battery swap station. This station allows the entire battery pack to be swapped out in about 90 seconds, or less than half the time it takes to fill a gas tank, without getting out of your car.
The way co-founder Elon Musk described it was that you can choose either fast or free when you need a recharge. You can charge your Tesla in about 30 minutes at a supercharging station, or you can pay around $60 to swap the entire battery pack and keep on going. You have to come back on your way back through and get your own pack back, or pay the difference and keep the new pack.
Once these stations are built, at a cost of $500k per station, there will be no reason you couldn't make a long trip across country.