From Wikipedia's entry on Con men and popular cons:
Stolen Cheques. A recent twist on the Nigerian fraud scheme, the mark is told he is helping someone overseas collect "debts" from corporate clients. Large cheques stolen from businesses are mailed to the mark. These cheques are altered to reflect the mark's name, and the mark is then asked to cash them and transfer all but a percentage of the funds (his commission) to the con artist. The cheques are often completely genuine, except that the "pay to" information has been expertly changed. This exposes the mark not only to enormous debt when the bank reclaims the money from his or her account, but also to criminal charges for money laundering. A more modern variation is to use laser-printed counterfeit checks with the proper account numbers and payer information.
This con is what recently landed a guy in jail, for merely asking his bank (BofA) if a craiglist scammer's check was legit or not.