If you have a smartphone, why not use it as your business card as well? Instead of carrying around a stack of paper cards, I have taken a picture of my business card and stored it in my iPhone – ready to be emailed at a moment’s notice. Since you never know when you may need to give someone your card, this way you always have one with you and can just email it to the recipient whenever you need to. Here is what mine looks like in my phone:
Could I just write down my info for someone else when I needed to do it or when I forgot my cards? Sure. But this is a lot cooler and a lot simpler!