How can I transfer data from an iPod or iPad to my Mac?
I prefer iPhone Explorer from the same company that Mike suggested: Macroplant
It doesn't have a transfer limit and has almost the same functionality: http://www.macroplant.com/iphoneexplorer/
My personal favorite is Pod to Mac.
http://www.macroplant.com/podtomac/It can transfer pretty much all data including contacts, calenders, photos, notes, ...
The free version is limited in amount of data you can transfer at a time.
File Magic ($3 on iTunes) is an excellent way to do this.