Copying this verbatim from dear friend Sumana’s blog, because it bares repeating….
Yes You Should Have Business Cards: Left-justify your name and web address and email address — no title necessary — in a legible font. Get the perforated cardstock and do it on a home printer, or get a local copy shop to make them for like $20 for a hundred cards. Black type on white non-glossy paper is great; that way it’s easy for the other person to write on it to remember where they met you and why they want to follow up with you. Carry them with you. Put a few in your wallet. If you feel silly about it, think of it as an act of hospitality. You’re making life easier for people like me.