Fred Light, recently started a discussion in the PFRE flickr discussion group that is worth highlighting. Fred's post points out a tuaw.com review of the Square credit card reader designed to make it easier than ever before to for individuals and small businesses to take credit card payment anywhere without having to have a merchant account.
This product is available now for the iPhone and iPad and Android devices. You get the little square reader and the swipe App for free and pay 2.75% + $.15 per swipe.
The primary benefit of a device like this for real estate photographers is it allows you to take payment for a shoot on site at the shoot. Requesting payment via e-mail invoice and allowing customers to pay on your website is also is an easy way to get payment but you are always going to have clients that aren't as comfortable with paying online plus there is an advantage to taking payment right at the time they are getting the service. This is an easy, inexpensive alternative way to get your payment at the shoot while you are both are thinking about it. As Fred says, "I swipe the client's credit card. Then I take a photo of the house. They sign the phone. I email them a receipt with the total amount, and the address and photo of the house! The money is transferred (less the fee) to my bank account the next day. Simplifies my life and I get paid immediately!"