Here is a fun design.  I love the grunge effect.  It's stylish and modern and I love the randomness of it. Here are a couple of examples some grunge style calling/business cards.

black and white - grunge - calling card- business cardpurple - business card - monogram - grungegrunge business card - monogram - business card - black and whiteteal - turquoise - business card - calling card - small business card - grungeSo, how do you make a cool grunge effect?  First, you need a texture to draw from.  You can make your own by taking a picture of something with texture, such as a rock and importing it into a photo editing program, such as GIMP, which is free and extremely powerful.  Next, use the select by colour tool . Choose a texturous part of your image and click.  If you are getting too much or too little selected, simply adjust the threshold accordingly. .  Once you have selected the portion of the texture that you want, copy the selection (ctrl+c), open a new layer (the white button on the bottom left) and paste your selection on the copy (ctrl+p).  Then, click on the eye beside the original image to make it disappear.  To make your selection grayscale, click on colours, then desaturate.  You can also give your grunge layer a bit of transparency, so it blends into your background better (in the layers dialogue, make sure the grunge layer is selected, then move the opacity arrow to the left).