Tammy M
Shape can play a large part of getting your business card noticed and remembered. Here are a few ideas about shape. I saved this one for last because there are some really good ideas and some really bad ideas out there.

How about a round shape to a business card? It makes your card unique, noticeable, gives you some cool ways to put your information on the card with the look of the font or graphics. This card will definitely stand out.
Here is my opinion surrounding, (no pun intended) a round business card. I have gotten a round business card in the past. At the time I thought it was a good idea and noticeable. Today, I can no longer find the round business card. Why? Well for one thing it did not fit in any business card hold and it did not stack properly with other business cards. Because I could not store it properly, it kind of floated about on my desk. I either had to store it alone somewhere or cut or fold the card to fit into my card sleeves to store it with other cards. If I cut the card I removed important information. If I folded the card it made my organization weird (I have a little bit of OCD with it). Therefore, I did not carry the round card with me because it became a burden to manage. Now, I don't have good feelings about the card because it just was a problem and life is hectic and those feeling transferred to the person who gave me the card. I got to where the next time I saw them I wanted to give them back their business card. I just did not want to deal with it and over time I simply lost it. Not good.

The conclusion? You can go for a unique shape but make sure that it fits into the card sleeves most organizational systems that people will use.

Here are some good ideas.
Your shape of your business card can reflect your business. How about if you are a restaurant, you can have teeth marks embossed into the card or just have a bite taken right out of the corner. If you sell makeup, you could have your business card resemble a lipstick or compact. As a chiropractor, maybe shape it like a bone. If you sell alarm systems, you can have the edge of the card look like it is scorched or burn a hold through the middle.

Some business cards can serve a function such as a bottle opener, a letter opener or a note pad.

You can be unique and extreme but make sure you think about the recipient of your card and what they are going to do with your card. Your goal is that others will share it with others to show how unique it is.

Make sure you can write on the card. In my pile of cards I kept some that were pretty dark colors. This particular card was two sided with the dark color on both sides leaving no ability to make a few notes on the card. 

I added a note to my design to not have both sides completely full AND I will have to lighten the color to allow for reading of ink on the card.