Definitely pictures.. we are a visual business.
Go through your sports portfolio... find 1-4 images that just jump off the page at you and use those....
Looking at your online port, my first impulse would be to take something like this one:
http://www.pbase.com/mrcpix/image/84665999
Photoshop the crap out of it so that only the pitcher, ball, grass, and mound are left.... place it to the right side of the card, fill the rest in with white or black.. and use the negative space to the left for your contact info.
If you are shooting (or wanting to shoot) more than just baseball, it might be better to get multiple images (up to 4, more than that and they are too small)... one from each sport you've shot... for the front to show that you don't shoot JUST Baseball.