The ability to turn a smartphone into a portable credit card swiper makes sense for small business owners on the go, as well as anyone who happens to be out of cash. Like Square, the new ROAMpay device plugs in to the audio jack of your smartphone. Using the company's app, you get the same functions as using a traditional credit terminal with a platform that's available on iPhone and Android.

The ROAMpay swiper is compatible with the iPhone and iPad, along with Android smartphones like the Nexus One, HTC Hero and... here's the list.

It also comes with software that allows the merchant to email invoices and receipts to a customer, check transaction histories and sales reports online.

ROAMpay claims to offer low rates on credit transactions and will protect customers' personal information (being PCI certified- Payment Card Industry). All customer data is encrypted automatically when swiped and entered into the merchant’s cell phone and no personal data is retained.

Here's ROAMpay's video demo: