The website AppStorm recently put up a list of 100 free and useful iphone apps. Many of them probably work on the ipod touch as well. Here is a link to the list for the iphone
and for the
The site AppStorm aims to bring reviews of great (and not so great) Mac apps, and sorts them up into categorized lists, give you how-to tips and tricks to get more out of them, and combine it with a healthy dose of Mac related news.