You can do it in Word, using the Labels feature... by picking a business
card label product (such as Avery 8869, for example). Even if you don't use
the actual Avery product, you can still use the labels feature to set things
up... print them out on card stock, and then slice them yourself with a
paper cutter.
Exact instructions would depend on which version of Word you're using. In
Word 2007, click the Mailings ribbon tab, then click Labels, Options button.
There, set the desired vendor and product number (Avery US Letter [that's
the size] 8869, for example)... click OK... then click New Document. Word
creates a table with card-shaped cells for you to create the business cards.