I'm not a strong supporter of business cards nowadays. It's not because they don't do any good, but because most people are throwing them in the trash bin without even visiting your website and seeing what you do. Despite of that it's good to have some in your pocket. Here is my solution to using a special type of business cards that your potential clients may not throw away.
I've seen lots of great ideas for a business card for photographers. Some resemble the screen on the back of the camera, others show stylized symbols related to photography. The most common theme is using a business logo. All these may look cool but they have nothing to do with the main reason people hire a photographer: if they can get nice pictures from them. People may be impressed by your logo, but this doesn't tell them if you're good at your craft. People may be impressed by your smart popup-book-like business card, but that's mean you can take good photographs.
Society today is lazy. Unless you send them a link they can click on, few people will type your website address from your business card. That's the sad truth. There has to be something that would overcome their unwillingness to retype your website address. Lots of us have clients because some of them have seen an image of ours. They went to our website because of that and hired us. In my opinion, the business card of a photographer should show one or more images from the portfolio. This way the potential client will know if you are good right away without even visiting your website. That's a simple but working solution.
Here's what mine looks like:
On the back of it, I have my website, email, and phone number. The front side shows images from my portfolio, so if people like them, they may be interested to hire me even without going online.
That's my idea of a business card: a physical portfolio and contact information in the palm of a hand. With such business card, you don't have to spend hours and hours on making something creative that doesn't have anything to do with your portfolio. Your portfolio is your business card and your business card shows your portfolio.