I know the idea was floated around here before but it looks like tesla is implementing it. They are setting up battery hot swap units at some of their recharge stations. It takes 90 seconds to pull in, have an automated system remove the cooling system & battery and replace it with a fully charged battery. It will cost you $60-80 for this service which is about a full tank of gas in some cars but you only get 200 miles on the battery.
Alternatively you can get a free charge from these stations but you have to wait 30 min for the battery to charge up.

Gone in 90 Seconds: Tesla's Battery-Swapping Magic - Businessweek

 

z28x has been saying this for years Tesla owes him money for stealing his idea! This is impressive news though, Tesla is becoming a real contender in the car market place.

 

Pretty cool, I wonder how this would work on a Tesla that's been daily driven in the North East during snow season for a coupla years?