So folks, obey the visa rules of the country that you're travelling to. If you go abroad with a tourist visa and look for some "under the table" work you will have no recourse if the school stiffs you. In fact, it's a smart idea to obey the laws of the country that you're in. For me, that means honoring my contract and not mounting one-woman protests about aspects of China that I disagree with. For others, that might mean not smoking weed. For some unknown reason, a 24-year-old ESL teacher recently traveled from South to North Korea, ripped up his visa and asked for asylum. He's now begging to get out as he begins a six year sentence at hard labor. Whatever this young man thought he knew about North Korea, it's clear he didn't know enough.
Whatever you do, don't fall prey to a scam like this poor woman. Under no circumstances should you forward large sums of money to anyone. Yes, you will need to fork out money for transcripts, passports, visas, and immunizations before going overseas, and you will probably have to pay for a medical exams and testing, but don't send money to anyone for "processing" or "application fees" or "opening a bank account."
Raoul's China Saloon is an online (natch) forum for ESL teachers and has a thread dedicated to asking for feedback about about employers and job offers. A good place to get help from seasoned expats.
I found my current position through Profs Abroad and recommend it for people looking for a university-level job. You are able to apply directly to the hiring institution, not through a third party. There's now a small subscription fee, but I think it's worth it.
I didn't know there was actually such a thing as snake oil. Snake oil cream is an inexpensive unguent used for joint pain. It's considered to be old-fashioned and only for old guys, like Geritol.