I love my ipod touch. I have it on me all the time. It has been really helpful in tracking my food using the sparkpeople application. I take it with me when I run and when I have some down time i read some of the articles and message boards on the sparkspeople website.
I use the contacts, calendars, e-mail, and some other applications all the time. My new favorite application is the Coach 5K. It helps you get back into a running routine. Love it! Hope that helps.