I use intuit (like square), and it's great. I understand some of the concerns with processing cards through the iphone or other mobile defice. Before this the affordable option for mobile businesses was the old fashioned knuckle buster, and then go home and process through the computer, which I think is just as unsafe if not more so. First you are still processing through a computer but you also have a hard copy of the customers CC#, along with their name address and phone number, as well as 3 digit security code, and expiration date. And to avoid charge backs you need to hold onto this slip for at least 6 months. To me that is much more unsafe. If a customer is completely against me processing with my phone I'll do so manually, but so far my customers think it's great.
Aundrea