Here is the Automatic Jailbreak for Intel based Macs, the creator is making one for PPC later, and is supposidely going to release a new version that allow you to automatically install iPhone applications, and use Summerboard with ease.
http://code.google.com/p/ijailbreak/
You need to move the ENTIRE folder into Applications, and then open it, and click on the iJailbreak application inside of it. You also need to rename your hardrive to "Macintosh HD". Just follow the steps that pop up. The first one is to go to that website. The whole process takes like 10 minutes maximum, mine took 5, the first few minutes make it look like nothing is happening but it is running all the commands that you would otherwise have to do manually.
IT WORKS, it has worked for me, and lots of other people, there have been very few problems, just follow all the steps carefully, and of corse you iPod Touch needs to be plugged into your computer with iTunes quitted.
Here is the website that the creator posts new versions of iJailbreak at:
http://ijailbreak.com/
Here is an article about it at gizmodo:
http://gizmodo.com/gadgets/breaking/...ool-310672.php
And here is a video on youtube of how to use the automatic jailbreak:
http://www.youtube.com/watch?v=gmP3hvs5P9I