PTO Today recently partnered with Payschools. They work exclusively with schools and school districts. We think it is a great service for many reasons (better controls, less chance of theft/loss, easier for parents, etc) Read more about Payschools here www.ptotoday.com/plus/Payschools1006v3.pdf
You could try PayPal: www.paypal.com/.
Go to the Merchant Services link to get more info. I use it as an eBay seller and haven't had any problems at all. You will have to pay a small fee for every credit card transaction but it may be worth the convenience.
Does anybody have any tips on how to let parents pay for PTO things like, dues, tickets for events, school t-shirts/sweatshirts, etc using the internet. Many parents have asked me if they can pay for stuff online using a credit card.