http://www.microvisuals.com http://www.microvisuals.com/businesscard.jpg
I went for the matching approach in regards to colour and simplicity. I think that if someone sees your business card and decides to visit your website, they sort of have an image of what to expect. In this case surprise isn't too much of an important factor due to the potential clients possibly venturing into a whole new aspect of business or the internet. As familiar as possible in this case is the best (in my opinion).
Business cards are very strong for marketing, networking and brand awareness. It puts a small, pocket sized and distribution enabling physical front to your business in the public eye and in the grasp of potential customers.