I've been using WePay to manage sponsorship payments at http://hackersandfounders.com. I love the service, and if I could, I'd buy stock in the company.
If you want to go international you should get in touch with these guys: http://www.gluepay.com/
They do instant withdrawals/deposits to bank accounts, AFAIK they currently cover most of Europe. I have no affiliation except a former colleague works there now.