I use Premiere to capture single frames of video. 
First I capture the clip, toggle to the exact 
frame I want, then go the the pull-down menu 
under File marked export. Under this menu is the 
option to export a single frame. I then can take 
it into Photoshop and alter it. You can print it 
from there as well. I'm not positive, but I don't 
think you can take screencaps from Real Media. I 
certainly can't import it into Premiere (which 
sux). So if you want to capture video you'll need 
a capture card, and some sort of editing 
software. (Usually a capture card will come with 
a basic editing package) Hope this helps!

Megan