shift - S or rather alt-S, will take a screenshot of either actual in game play, or from the in-game film viewer (not the ahfilm.exe that you saw in most of my shots), alt-s will do nothing in the offline viewer.
the post directly above yours is a screenshot from the in-game viewer cut and edited for size, the rest of the above are from actual in game screenshots and the offline viewer, cut/pasted and edited into one final product.
the easiest way would be to use the in-game viewer (the "film" button on the splash screen) and watch the film and hit alt-s to take a screenie. it's of course saved as a huge 3 meg .bmp file that you should convert to .jpg with a program like ms paint (save as...). it'll be much smaller, but still most likely too big to post on the boards. there are other programs that will compress and reduce the pictures to a managable size, probably sacrificing some quality in the process.
however, what i gather you're really asking is how i managed to snag a screen capture of the offline film viewer (and combined it with an in game screenshot).
i call up the film viewer.. determine what point i want the screen capture to be and pause the film. then i open ms paint. then i hit the print screen key (and here you thought it was a relic holdover on keyboards with no use. you might have to do something to enable that print screen key to work - it's been so long since i did that i forgot what i did, hehe.)
after hitting print screen, i go to mspaint and "edit" and "paste" what it did is captured the whole of my actual computer screen. then i simply cut out what parts i wanted to use and open a new file and edit/paste that cut to it then save.
if i want to add something else to that i repeat the process and add that new piece to the one i just did. since it'll still be too big, i cut out only the part necessary to get it to a postable size (takes experience to know about how much you can do - all of mine were about 60-80kb for the final product).
when i'm happy with the finished product i save it as a .jpg. i leave them as .bmps til i'm done because mspaint can't edit .jpg to my knowledge. other programs can.
does this answer your question?