I want to make my way from San Diego to the bottom of South America(Chile) by bus, train, foot, etc. what are the top five things I should prepare for?

You’re going by yourself? That’s very dangerous.

A gun, bullets, money, tent, and a backpack.

Learn Spanish so you can communicate.
Carry some means of sanitizing water so you don’t get sick.
Wear good, broken in shoes.
Get a money belt and keep your cash and identification documents secure.
Pack lightly.

And check out the South American Explorers Club. Their club houses are very nice, and you can often find both traveling companions and travel advice from them.

@MrGeneVan – Don’t take a gun or even a few bullets across the border into Mexico, unless you want to spend considerable time in a Mexican jail.

Wikipedia has an excellent article on the Pan American Highway, with references to other sources. You can get some great tips and ideas.

1) Bribe money
2) Kaopectate
3) A mobile phone with the American consulate of each country you are passing through on speed dial
4) Spanish lessons
5) A will prepared in advance of your trip

A knife
A pair of bolt cutters
Close toed shoes
A couchsurfing membership
Travelers cheques (those things are excellent)
A passport
Other ID
Water sanitizing pills
Vaccinations beforehand

My answer was half tongue-in-cheek. I think driving through Mexico right now might be a little too dangerous as it is. There is a guy who works next to me who emigrated from there and he has cancelled his annual trip home because of the explosion of violent crime in Mexico. I think if you really want to do this I would make certain I spoke Spanish or travelled with someone who did. I would also try to travel by rail instead of auto. One of the problems with car travel is that many of the rural gas stations in Mexico often run out of unleaded gas and you have to wait until the truck comes to refill the tanks. As for the Central and South American countries, I cannot say.
If you do have your heart set on driving then I would suggest you drive down the Baja peninsula and then take the ferry across to the mainland. Baja is a little safer for travelers as it is a tourist economy and thus the police are (supposedly) less likely to harass you. Also, there are more Ángeles Verdes on the highway in Baja.
Whatever you decide, have a fun and safe trip. Good luck.

One more thing if you drive. After you get a few miles south of Ensenada, the asphalt on Highway 1 gets really thin and there are tons of potholes. Your best bet is to find a semi to follow. The truck drivers know all the potholes and you can just ape what they do. There is no train that travels down the Baja Peninsula so everything is trucked. Because of this you’ll find no shortage of trucks to follow.

Prepare for diarrhea, being robbed, having trouble communicating, finding a Denny’s, and big bugs. Oh and lots of adventure so who cares about the minor inconveniences.
<——likes his adventure 5 stars with room service

South America is not like Europe where people are expected to have some level of English ability. In the rural zones where you will probably spend much time traveling through, communication will be damn hard if you don’t know spanish.

I really think it’s a bad idea to go alone, even if you are a spanish master. Parts of south and central america are not all that safe, and much less safe for someone who doesn’t know the area and is a traveler. Rural america and rural latin america just don’t compare, rural latin america is much more poor and much more remote,

Actually, in some places it is helpful to speak Quechua, Tzotzil, Tzeltal, Aymara, or even Guaica or some of the other native languages. Or find a guide who speaks them.

What to prepare for:

1) armed drug cartels
2) dysentery
3) corrupt law enforcement
4) roving gangs of kidnappers
5) hot latin chicks

Coke, good food, bad food, god women, bad women… Beggers….

I have a worker from El Salvador. Over the last 5 years three of his brothers have been killed in robberies. I have a friend who has a home in the Dominican Republic. He saw a policeman shoot a man dead on the side of the highway at what appeared to be a traffic incident. Be careful. As to the coke…I would just drink the liquid kind.

As per the mamasitas, estan muy caliente…recomende Trojan.