Hardware & software:
- FoxMarks at http://www.foxmarks.com for free from Leo Laporte.
- Bonzai3d at http://www.bonzai3d.com for free from Alex Lindsay.
- PathFinder at http://cocoatech.com for $39.95 from Bobby Llewellen.
Books:
- Apple Training Series: AppleScript 1-2-3
from Andy Ihnatko.
- Beginning iPhone Development: Exploring the iPhone SDK
from Andy Ihnatko.
Bonus:
- Check out http://www.llewtube.com