Business cards are the best way to make a great first impression with potential clients, and so it helps to get as creative as possible. Creative business cards are an industry unto themselves, and by taking advantage of them a person can leave a great impression.
Almost everyone uses the basic card, with its block of information and a logo. The main difference comes in the card itself; not all cards use card stock, after all. Clear plastic cards are becoming more popular, as are slim metal cards; these are distinctive and therefore stand out. Other cards open up and flip out, making them a little more fun for people while allowing the person to give a little more information about themselves.
These cards show that you go the extra mile to impress, so definitely use them to show clients why they should hire you.