Biologically, a hangover is dehydration. The best way to counter it is to hydrate yourself with electrolytes. They now make little packets you add to water specifically for this purpose. My husband prefers the cheaper alternative...pedialyte packets. You have to drink this BEFORE you go to sleep, though.
So I don't get hangovers , but when I'm drinking I like to hit up a White Castle or a chili place here in Cincinnati (Skyline), I usually get the chili/cheese coneys. Back in high school, I would always go to Zantigo (Taco Bell-like mexican only ALOT better) the next morning. There was one up the street from my house so it was a quick walk.
I would not recommend as to not knowing the garden hose you might usee but numerous times drinking from a garden hose has helped me.
If no suitable garden hose is available I usually try gatoraide