In order to attempt this Jailbreak (Which neither I nor this site recommend or take any responsibility for as it voids the warranty and may render your Kindle unusable if something goes wrong), head to this site and follow the instructions included in the Zip Archive’s README file. This involves nothing more than connecting your Kindle to a computer, copying a .mp3 file to your music folder, disconnecting from the computer, and running the music player. A button pops up labeled “Press to Jailbreak!” and you’re done.
My trial of this process went smoothly and did pretty much nothing. It is definitely anything but an urgent need or an inherently beneficial act for most people. All you are doing is enabling root access to your device, which means that among other things installing third party software will be possible. Chances are good that even with this it will not be possible to open up general 3G internet access, use of neglected hardware like the internal mic, or removal of advertising, but other than that there shouldn’t be many limits.
If you are interested in the potential that the process opens up, I would recommend both acquiring your Kindle Touch in the near future and making sure not to allow any software updates on the device until it is certain that the changes will be kept around. While Amazon has been incredibly open in their lack of interest in securing the Kindle Fire in any significant way, they have a history of being somewhat more closed with their eReaders. Not the least important reason for this is the heavy investment the company has made in their proprietary format, the evasion of which would likely be the first thing that customers use their new found freedom to achieve.