Programming for the iPod
If you're fortunate enough to be using an iPod with a Macintosh, you can easily program your iPod. The iPod itself can be scripted with AppleScript. Apple even has a series of samples you can use to get started, and a collection of tools you can download to your iPod:
Clear All Notes is a script that deletes any notes on your iPod.
Clipboard to Note pastes any text on your Macintosh Clipboard directly into your iPod notes.
Eject iPod detaches your iPod from your Mac without having to open iTunes.
Notes from Webpages is a script that works only with Apple's Safari web browser. With it, though, you can save extracts from a MacCentral web page into your iPod notes.
Here are some additional scripts you can run on your iPod:
iPod It lets you store personal information manager (PIM) content such as address, email, and calendar info.
iPod Launcher enables you to launch programs from the iPod.
Pod2Go is similar to AvantGo, but for the iPod.
If you're serious about getting into how to extend the iPod programmatically, the best resource I've found so far is the iPod Hacks site. This site gives you all the tricks and tips you need to extend the functionality of the iPod. You'll even find information on how you can load Linux onto your iPod.