Not all of them are scams....
...I have just inherited £10 squillion from my tax exile great, great uncles, nephews, next door neighbour. I desperately need to smuggle this money out of the country so that the evil dictator Anthony B-LIAR doesn't get his hands on it. If you send me your bank details I will transfer all the money out, erm, I mean in to your account and let you keep half - honest!