Surviving the long haul
Overnight bus rides are a simple, unavoidable reality of travel. In countries like Argentina, whose "distance between population" index is highest in the world; in Africa, where even a 300 kilometre trip can take three days; and in India, where you'll probably get stuck on a train for a week before a space in the crowd appears for you to escape through, you need to be prepared deal with and thrive during these adventures.
Focusing on recent experiences in South America (because that's as far as I've been so far), I will hereby enlighten and inform about the best methods for conquering the overnight.
Words of warning
In case it isn't immediately obvious, overnights are evil because they involve sitting in one uncomfortable bus seat for anywhere between twelve and thirty hours. Your feel swell, your knees hurt, your bowels ache, you thirst and you starve, and your brain goes numb from either squinting at too many English subtitled movies or reading too many bouncy pages.
And you can forget getting any natural, comfortable sleep. Rough roads, crying children and livestock will dash any hopes of that.
Remedies and consequences
The best way to conquer the overnight is through unconsciousness, which many travelers achieve through sleeping pills. While guaranteed, in the right doses, to knock you out for the desired amount of time, they are not ideal. First off, they are addictive. Secondly, they don't actually give you natural sleep, so you will wake up groggy and confused. And lastly, being comatose for the duration of a bus ride leaves you prone to banditos (on sketchy rides), vandalism (when traveling with ass-holes carrying permanent markers), and missed all-important pit stops and smoke breaks.
Now, speaking from experience, some of the best nights sleep I've had have been caused by late nights in the bar. Recreating that experience on a bus is tricky, especially if your idea of a "night out" differs from a few brews at the pub. I strongly recommend against hard drugs, especially any amphetamines, on overnight bus rides. No one wants to sit beside someone who just swallowed two happy blue pills for twenty hours.
After extensive testing, the best mixology to follow is two to three cans of beer, one of which should be a tall can, or sharing a small bottle of whiskey. Be careful to avoid dark beers (too meal-y), as well as very light ones (too quick to get through the system), as well as rye (too anger inducing), tequila (too party animal-ish, unless traveling in Brazil - see geographical indicators below), and absinthe (too hallucinogenic). A two to three beer range ensures grogginess, without excessive drunkenness, minimizes potentially nasty visits to the loo, and reduces the hangover threat. It also allows for a comfortable sleep that is easily interrupted by dangers.
The final coping strategy is a technological one. An iPod, or other inferior music-listening device, should be listened too the whole distance of the trip, with noise-cancelling inner-ear headphones. The key to this is to have a good selection of music - which should include nothing by Yanni, or any boy/girl band whatsoever - so that songs may be listened to at random throughout the night. If trying to learn the local language, a few language lessons are also good to throw into the mix (¿done hay lugares gay?).
A shout-out is in order to all those whose play-lists enriched my iPod before we left. Thanks to you, and the extraordinary battery-life of my iPod Touch, I once listened to 264 songs straight over a 27 hour trip, without having to skip a single one.
Geographical indicators
Now, whichever method of dealing with the long-haul bus trip you choose, the shock of an unfortunate wake-up in the middle of the night can be disorienting. Here is a short guide to a few South American countries, should you ever find yourself busing through the continent.
If you wake up in the middle of the night and the DVD intro screen to a bootlegged version of John Rambo is playing, and has been paying for the last three hours, at top volume, you are probable in Peru.
If are woken up at a rest stop that has no washrooms, no resting places, and only one small wooden booth last seen being used by Lucy to give psychiatric advice at 5 cents a pop, and is staffed by someone very closely resembling the bus driver, or maybe the bus driver himself, and at which pop is, coincidently 5 cents, you are probable in Bolivia.
If you are awoken by a lively fiesta on wheels consisting of any two of the following elements, you might be in Brazil: music from cellphones, small battery powered radios, or the buses speakers; food, both cold and barbecued somehow; dancing; disco balls, strobe lights, or black-lights.
If it is two am, and you are woken up by the stewardess and offered a tray of dinner, or a friendly game of bus bingo, you might be in Argentina.
Recovery
Your best chance at recovery lies in finding the nearest ex-pat pub run by either Dutch, British, or American hippies, eating something woefully unhealthy, and drinking too much beer. Only at this point with the shaking stop, and will you be able to shake off the weariness, and residual wariness of the overnight bus trip.
D.

