Hold+ v4.0

Hold+ is the ultimate companion to the PSP's music player. It adds useful features and gives you TWICE the battery life when used properly.

It does the following when the Hold switch is enabled:

• Switches off the LCD screen and backlight.
• Underclocks the CPU to 60MHz
• Fixes malfunctioning Hold switch.
• The original screen brightness and clock speed are restored only when the Hold switch is released fully to the power off position.
• Prevents the PSP from going into suspend mode if you accidently push the power switch too far when turning off Hold mode.
• Turns off LEDs in hold mode.
• While in hold mode, allows the use of Left, Right, LTrigger, RTrigger, Volume and Start buttons, if you hold the Select button first. Useful to skip songs, pause etc.

Additional Features:

• Enables the 5th brightness level on PSP Slim.
• Increases the vertical scrolling speed of Music player by around 50% (scroll 300 songs in 10 seconds).

Usage:
Turn on the Hold switch to automatically disable the display and underclock the CPU. Release the Hold switch fully to the power off position to return the CPU to normal speed and enable the display.

Download: Hold+ v4.0
Source: psp-hacks