Optimize your iPhone using playlists

Whether you're an iPod guru or an iTunes newbie, setting up the iPhone presents a new set of challenges. The underlying dilemma is that you've got an amazing convergence device with only a handful of storage. Unlike an iPod, the iPhone's limited memory has to hold a robust operating system, applications, e-mail, and Internet downloads. The good news is that with just a few little tweaks, you can customize iTunes to squeeze the most from your iPhone.

With just 4GB, 8GB, or 16GB of storage, the iPhone does not afford you the luxury of holding your entire digital music library. Think of your iPhone as an iPod that needs to be kept on a strict diet. Like the iPod, the iPhone lets you either automatically or manually sync your iTunes music collection. This leaves you with four options: have your entire music library sync to the iPhone every time you connect to your computer; have only certain iTunes playlists sync to your iPhone; manually add and delete music; or prevent music from syncing at all.
Apple iPhone series
via [clnet]