A study at Granada University of Spain seem to suggest than beer is better than water at rehydrating the body after exercise.
Here's what the researchers did:
Asked 25 students to run on a treadmill at 104 degrees Fahrenheit to the point of exhaustion
Measured their levels of hydration, motor skills and their ability to concentrate
Half the students were given water to drink and the other half were given Spanish lager
Those who were given beer had slightly better hydration levels than those who were given plain water.