HTC -Magic - Smartphone - WCDMA Quick Start Manual page 34

 Quick Start Guide
To go to the extended Home screen
The Home screen extends beyond the screen width to
provide more space for adding icons, widgets, and more.
Slide your finger horizontally across the screen to go to the
left or right extended Home screen.
Tip
While on an extended Home screen, press HOME to return to the
main Home screen.
Refer to the User Manual PDF for more details.