Activities for an iPod School Listening Center?

Hey Classroom 2.0 Community!

I am trying to brainstorm how I can use this new piece of technology to engage students.  I have never used a listening center before but have heard great things.

What are some of the pros/cons of a listening center and what is your personal experience?  Also what are some activities I could use with this?

A short list of what I have:

-Audio Books

-Make my own activities

-Can help language learners

-Can help teach children to read