There is now a jailbreak for it, the programme is called Blackra1n, it has been found that it can jail break all the ipods (even 3rd gen) and iphones, to get it go to blackra1n and click the windows button at the bottom of the web page. This will open up the file to be downloaded, then open it up, click make it rain and in about 30 seconds it should be jailbroken. The only thing about using it with the ipod touch 3rd gen is that it is a tethered jailbreak, so if you turn the ipod off and try to reboot, then you need to reconnect it to the computer and click make it rain, to jailbreak it again, this time it takes less than the orininal. But if you don't want a tethered one then i would say wait a while for the dev team to release one soon.
I downloaded a package called SBSsettings from cydia beofre i downloaded stuff like winterboard and installous. This gives you the ability to respring the device instead of rebooting it, as when you are downloading the major files such as winterboard it makes you reboot the device, therefore loosing the jailbreak. This i found helped me out alot
i just purchased a 32GB ipod touch 3rd Gen, so far yes a tethered jail brake so far.. i rebooted it once just to see what happens.. yea just plug in the Ipod to your pc and make it rain again.. bang done... yes cant wait for a NON-tethered jail brake.. remember dont update if ya dont need to.. no point...