Opteka releases a dual cold shoe bracket that mounts to your camera's hotshoe. It's a simple way and inexpensive way to mount two accessories directly to your camera such as an LED light, microphone, or audio recorder.
The Opteka looks to have a shorter profile, but it is very similar to the Dual Light and Sound type bracket found below.
Photo Video Dual V Bracket for Video Lights & Microphone
If you really want to load up on your hotshoe, another slightly more expensive option is the Alzo Multi Mount. This includes a microphone / portable audio recorder shock mount, 4 cold shoes, and 1/4-20 holes for even more accessories. It can be used on the camera, but we often use this type of mount on a light stand config (seen below).
(above) Our Alzo Multi Mount Config