Well, I have always found this aspect of sex fascinating. I remember when I was younger watching porn with my buddies, we always liked DP videos and always discussed a desire to try it, but whenever a DVP vid would show, they'd be reluctant to say they would like to try that. Usually the standard response is "two dicks touching each other is kind of gay".
Were they right? I don't think so, but everyone has their own preference or their own personal boundary.
I love to see DVP scenes and Double Blowjob scenes, but in particular, I find a fascination to what Mark Max was talking about where a girl is in control of the two cocks, she has them pointed at each other occasionally licking and sucking them as she pushes them together, rubbing against one another and twirling them around each other until they both explode. I enjoy watching the position where two men lay in a scissor position where their cocks are pressed against each other and the girl sucks on them both and jerks them together. I've found a couple of scenes like this, especially in German/Euro pornos, but nothing where that is the primary focus of the video.
Unfortunately, it seems that whenever you can find a clip like this, it is usually only a very short portion at the beginning of a sex scene. One could only hope that as the popularity of this type of sexual position grows, there will be more full-clips of double blowjob/ girls rubbing cocks together till completion videos.
Great posting site, and I look forward to checking out the clips recommended and some of the other forum sites where this topic is discussed.