Yeah, it's actually not so much the particular tool, since as you pointed out pretty much any modern photo editing software could have achieved this effect. Rather it's that with digital photos and editing effects like this are so much easier to make. This same image could have been made on film but it would have been very hit and miss without a lot of experimentation with exposure and lighting. I'm disappointed when people post images that they have obviously not spent any time post processing. I've found the challenges lately have show cased some interesting talent.
With digital pictures, double-exposure photographs are necessary made by software nowadays. The value is not in the tool (most digital picture editing software allow to do so), but in the way you chose to create this image.
A while ago, I took a stereophotograph with a reflection that looked like double-exposure. I saw potential and than searched inspiration about this technique to compose another one, but although I found a lot of technically good pictures, they did not trigger my creative personality facet.
That's why I like this photograph: the way you used it really tells a story, especially when coupled with your title.
Thanks for the compliments. I'm quite happy with my new pair of Sony a5100's low light performance (especially compared to my old Canon A810's). The market was a bit darker than it appears in these photos.
Mike, I'm using a pair of Sony a5100's sync's with a multiport cable. More information and pictures can be seen at: http://www.3dphoto.net/forum/index.php/topic,11976.0.html
Thanks for the comments. This was a rather quick and dirty composite to satisfy Timo's request. I didn't even bother to re-render the V-1 (it's a horizontal flip, lettering is reversed and the cable channel is on the wrong side). None of the background was 3D converted (except for the barrage balloon). That might explain Timo's "flattened" comment :)