If you want to let a potential employer or know how to get a hold of you, the best and easiest way to do so is to have business cards on hand. Can you imagine what the head of a company asked for your business card and you told them to hang on while you ripped a piece of paper off to write down your phone number? Needless to say if that was the case for you, the job was likely given to someone else.
If you want to really impress those who get your business card, you should check out the business card that comes with a circuit board. Using the optical illusion called “persistence of vision” you can wave the card in front of you while LED lights flash your name and number. Although you may not want to actually pass these out as serious business cards, they are still pretty neat (if a bit hard to read). At $2 a pop, you could hand them to people who might get a laugh out of it, but if you want to mass produce cards, you may want to think again.