Altho slightly less convinent than jumping in the car, the following tips will help save your life and the lives of people around you.
Public transport. Lookup bus, train or tram times before you leave the house.
Arrange a lift with a friend or relative who isn't drinking.
Taxi. Arrange to share a taxi with a group. You can split the fare and carry on partying in the comfort of a friends home!
Before undertaking a long journey, be sure you've had plenty of sleep and take breaks at no more than 2 hour intervals.
Avoide night time driving
If you begin to feel drowsy, pull in somewhere safe for a nap. NOT the hard shoulder.
