EBay does not allow sellers to advertise that they accept non-electronic payments. Listings with "I accept money orders and checks" are slated to be removed under the rules. Enforcement was held off until January (I'm not sure what date they actively begin or began enforcement).

EBay does not prohibit sellers from accepting those forms of payment, though - they just can't advertise it. You can send a message to a seller and inquire. Many sellers probably think they are prohibited from accepting checks or money orders, so don't be surprised if you receive a negative response or none at all.

EBay has recently added two more forms of electronic payment services to its approved list. PayPal is not the only form accepted.