Keep it efficient! Included in iTunes 9 is the ability to encode audio using High Efficiency AAC. This is a special audio codec that allows for very small file sizes with very little perceptible degrade in quality. You probably don’t want to use this for your music library, but it is a great tool for throwing up audio files with a small foot print on the internet.

To use it, go into iTunes Preferences, and then click the General tab. Click the Import Settings button, select the AAC encoder, and then choose Custom. From this window, make sure Use High Efficiency Encoding is checked. You can then configure the setting to your taste.

High Efficiency
High Efficiency

Photo Credit: cesarastudillo