It wouldn't be unreasonable of you to ask "who actually wants to change their voice for online gaming?" When presented with Morph Vox Pro it was the first thing that popped into my mind.
Morph Vox Pro allows you to tinker with your voice to make you sound different to how you actually sound. The default voices you can take on as your own are as follows: a child, a demon from hell, a robot, a man, a woman and bizarrely a dog that translates your voice into barks.
You're not limited to keeping those voices, there are plenty to download online and you can also devise your own with the built in programmer. You can add pitch shift and timbre for the most obvious differences, as well as tweak with background and special effects to come up with your own voices.
The problem is that these simple options only provide simple results. In fact there's not a huge amount of difference between the various voices (apart from the dog barking which is just strange). Male voices are deep, women and kids are high pitched. The asexual creatures like the robot are probably the highlight, with a kind of 80s style electronic twang to it.
We still haven't answered the question of who exactly would use this program. My only guess is those of you who like doing prank calls on friends, or perhaps are interested in really role playing when playing World of Warcraft could find a use for this. Generally though, most gamers won't ever use this software.
Below is a picture to give you an idea of what the interface looks like. Where do you think you would use Morph Vox Pro? Let us know in the forums.