There is also a re-shipping scam, when they will ask you to re-ship goods for them.
These goods are purchased with stolen credit cards.
Usually they say to keep some money for your trouble.
Needless to say, those Money Orders or checks are no good, and not even worth the paper they're printed on.
If you cash them or deposit them into your account, Money Orders or checks will come back after few weeks as fraudulent and you will be responsible for paying back the money to the bank and sometimes even charged for passing counterfeit instrument.
Recently there are also Nigerian scams originating from Malaysia, China, India, Turkey, Spain, Cyprus, Egypt, as that's where Nigerians are located since they can easily get to these countries without visas or on the student visas.
Men are usually widowed engineers, building contractors, military, vet doctors, surgeons or antique dealers.
Women are usually nurses, models, charity or UNICEF workers or antique dealers.
After they establish some lovely correspondence with you, fall in love and maybe even send a couple of cheap presents, they will either: a) be almost on their way to meet you, but something will happen to them: they will get robbed, beaten, get into the hospital, or other misfortune will happen and of course you will be their only contact to ask for financial help, or: b) tell you that their employer pays them with Money Orders or checks, and they can't cash them in Nigeria.
Nigerian scam comes in many forms: 419 scam, when they offer to transfer millions of dollars into your bank account, or lottery scam, when they tell you that you've won something in some bogus lottery.
However, Nigerian dating scam (or romance scam), besides just asking for money for their studies, sick relatives, etc..