I like naked URL’s myself. Like how a human feels naked, it’s freedom, unrestricted from cumbersome apparel. Same with your URL. On your business cards and other printed materials take off the “http://www…” from your website address and you’ll have a simple, pleasing appearance. It becomes easy to read and the .com ending is your clue that this is a URL. You can type any URL address with or without the “http://www..” and get to the same web page.
Tech SEO experts will tell you there are some consequences to using either. My point of view is that as long as you are consistent with your choice you will be okay.
(The definition of a URL is the address of a World Wide Web page for those of you who are website newbies.)