Hi, I'm back. Had a heck of a "day job" work day yesterday and been deep head-first into a bug fix for Seamless Donations. Catching up to other posts now.
I believe donors must have a PayPal account. I have had requests for additional gateways, some of which include pure credit card processing without a PayPal account, but it's a pretty big project. It's on the list, though.
--David