[kaiserama]

I have used PayPal and Google Checkout on a site, if you sign up for the business/payments pro version of PayPal you'll be able to collect payments in 2 ways on your site. Either via PayPal payment, or credit card. The credit card payment can be transparent to the user if you are either using a shopping cart with PayPal integrated or if you know how to program against the PP API, or can transfer to PP and complete a CC transaction there. The Google Checkout option will require the purchaser to have a Google Checkout Account. This is typically a slight deterrent as it requires someone to create a new account which can sometimes be considered a PITA.

Either way many sites typically support multiple payment methods. But if you're talking about small transaction sizes you may want to do some research into micro payment processors. Not sure how far along they are but one that had been mentioned a long long time ago was NOCA. Think the site is NOCA.com. But there are others.

Good luck.

oh and yes there are always premiums involved. If you go with PP the fee for payments pro is like $20/mo + ~3% + $.30/transaction. Services like Authorize.net and Cybersource will have slightly lower transactional rates but higher monthly fees.