Take the Custom Bracket Mini-RC. It's a beautifully made flash bracket that positions the speedlight beside the camera and not above it. While it may not be ideal for direct flash, it works fine for on-camera bounce flash, so long as you use the Black Foamie Thing to prevent direct light from spilling on your subject. It's main tributes are its sturdy construction and flat contour, making it both rugged and easy to carry. In this quickly made photo (Photo #1), you can see the flash placement, and how the Mini-RC gives some clearance for your hand to grip the camera. Sorry, but his is a very right-handed thing. I purposely avoided using the diffusion dome, since it reached just beyond the edge of the lens hood and may have introduced some lens flare.
I had a different purpose in mind. Since I had wireless iTTL control even when the main, shoe-mounted light was both a bounced key light, I could mount a "near axis" speedlight to serve as a fill light. Granted, it wasn't ideal, but I reasoned that if the relative power was kept low enough, the potential "double shadow" would not be noticeable.
The system is not without its pitfalls. Whenever bounce flash is used, there is always the problem of color contamination from the walls and ceiling. And while you can correct any tinting in post production, the direct fill light will always be "daylight". Depending of the color of the room, you may get some strange shadow tinting. These classrooms were close enough to "white" to not cause a problem, but I have encountered situations where it has.
The setup worked well for posed shots, where you make one or two quick photos, usually adding the "uno mas" option after the first shot. Again, when people know they're being photographed, the on-axis fill light can give you a bit of extra detail in the shadows.