PayPal 
Service allows visitors to send money and bills to anyone with e-mail, auctions, classified sites, and personal web sites.
http://www.paypal.com/WorldPay
Offers a range of e-payment and e-commerce solutions.
http://www.worldpay.com/
PPPay.com
Payments by email, offering a choice between instant and escrow payments.
http://www.pppay.com/
Payko
Allows sending money orders to several countries by payment from a PayPal account. Can be used for auctions where the seller does not accept PayPal.
http://www.payko.com/
