This comes from Handango: "Pocket Hack Master is an advanced utility that allows you to alter (overclock or underclock) the speed of your XScale CPU. Hack Master supprts speeds from 60 MHz to 472 MHz. Lowering the speed of your XScale CPU will add to your battery life. Or you can increase the speed if you need more power. Get detailed information on your device, system processes, threads, modules, system databases, battery and power

Requirements:XScale or StrongARM PocketPC device

Compatible Devices/Operating System: @migo 600-C, Acer n20, Audiovox Maestro PDA1032, Audiovox PDA1032C, Compaq iPAQ 31 36 3700 Series, Compaq iPAQ 3800 Series, Compaq iPaq 3900 Series, Fujitsu Siemens Loox, HP Jornada 520/540 Series, HP Jornada 560 Series, NEC MobilePro P300, O2 xda, T-Mobile Phone Edition, Toshiba e310, Toshiba e550G, Toshiba E570, Toshiba e740, Toshiba Genio-e, Zayo."

There's a thread going on on Pocket PC Thoughts with more information.

Apparently the 'trial' software does not adjust the speed, only shows the system information. But at US$ 9.99 a 50% speed up on certain devices would be cool.

Some tech stuff: to increase the clock of your H3970 or H5450 to 600MHz, you have to set the manual options to 27, 3, 2... According to some other info, don't change the L option too much, that controls some stuff in the LCD!

It also has a Scale option: you set thresholds for idle, low and heavy CPU loads and the software will change the clock speed accordingly. You can save power while not using it heavily, or get that "push" you need now and then. You can also check an option to always max the speed while in the cradle!