Is there any type of software that can digitize a video into signle sprites? I am looking for something to create enemy and weapon sprites for my games...

What do you mean by single sprites? What kind of file type are you looking for?

A screenshot program would seem to me what you are looking fore but alas i cannot help yuou there as I myself need that as well.

here are clips of the 3d realms team "digitizing" the guns. I want to do something similler.

ftp://ftp.3drealms.com/misc/duke3dvc.zip