UI Modifications

Change the thickness of scrollbars

To change the thickness of the scrollbars at the right/bottom of documents larger than the screen, adjust...
For the horizontal (bottom) scrollbar:

HKLM\System\GWE\cyHScr = 9 (DWORD decimal)

For the vertical (right) scrollbar:

HKLM\System\GWE\cxVScr = 9 (DWORD decimal)

The default thickness is 13. You can set the value to pretty much anything you like

Change the length of scrollbar arrow buttons

To go with changing the thickness of the scrollbars, you may wish to change the length of the scrollbar arrow buttons...
For the horizontal (bottom) scrollbar arrows:

HKLM\System\GWE\cyVScr = 9 (DWORD decimal)

For the vertical (right) scrollbar:

HKLM\System\GWE\cxHScr = 9 (DWORD decimal)

The default length is 13. You can set the value to pretty much anything you like

Enable ClearType in Landscape mode

To enable ClearType in Landscape mode:

HKLM\System\GDI\ClearTypeSettings\OffOnRotation = 0 (DWORD decimal)

To disable:

HKLM\System\GDI\ClearTypeSettings\OffOnRotation = 1 (DWORD decimal)

Note that your PocketPC screen's LCD red/green/blue ordering required for proper ClearType display is only correct for Portrait display. You may or may not prefer to leave ClearType in Landscape mode disabled

Change the display of the clock in the taskbar

The clock in the taskbar can be changed to show not only the time, but also the date, or just the date, or nothing at all.
To show nothing:

HKLM\Software\Microsoft\Shell\TBOpt = 0 (DWORD decimal)

To show just the clock:

HKLM\Software\Microsoft\Shell\TBOpt = 1 (DWORD decimal)

To show just the date:

HKLM\Software\Microsoft\Shell\TBOpt = 2 (DWORD decimal)

To show both the date and the clock:

HKLM\Software\Microsoft\Shell\TBOpt = 3 (DWORD decimal)

Note 1: If you switch to the Analog clock display, the date will remain visible -through- the Analog clock
Note 2: Setting the clock to show 'nothing' will still keep the reserved space, showing the taskbar background, and obscure any icons that will shift to the right.
Note 3: Your date may get obscured by the space reserved for the OK/Close button in the top-right. You can fix this my adding spaces at the end of your 'Short Date Format'. See also the tweak on 'Change the Short Date Format'

Show Edge network indicator instead of GPRS

If your network provider supports the Edge network (and your device does as well), you can use the following to show a little 'E' icon instead of 'G' icon when connected to an Edge network:

HKLM\Drivers\BuiltIn\RIL\EnableDifferGprsEdgeIcon = 1 (DWORD decimal)

To disable again:

HKLM\Drivers\BuiltIn\RIL\EnableDifferGprsEdgeIcon = 0 (DWORD decimal)

Note that your device -and- your network operator need to support Edge, otherwise you won't see it. Also note that if you connect to GPRS, you will still see the 'G' icon.

Add GPS settings icon

If you have a GPS device, you can add a GPS settings icon to your Start > Settings menu using:

HKLM\ControlPanel\GPS Settings\Group = 2 (DWORD decimal)
HKLM\ControlPanel\GPS Settings\redirect <-- delete, or rename, this value

Note that '2' stands for the Connections tab, '1' is System and '0' would be Personal
Note also that this has reportedly disabled one person's USB connectivity. To restore, set "GPS Program Port = None", "GPS Connection Port = None", "Automatic GPS Management = on"

Hide/Show Screen orientation icon

If you wish to hide the Screen orientation icon, shown in the task bar on some devices, you can set:

HKLM\Services\ScreenRotate\ShowIcon = 0 (DWORD decimal)
HKLM\System\GDI\Rotation\HideOrientationUI = 1 (DWORD decimal)

And to show it again:

HKLM\Services\ScreenRotate\ShowIcon = 1 (DWORD decimal)
HKLM\System\GDI\Rotation\HideOrientationUI = 0 (DWORD decimal)

If this doesn't work, you can try:

HKLM\Services\screenrotate = 0 (DWORD decimal)

And to show it again:

HKLM\Services\screenrotate = 1 (DWORD decimal)

Note that this icon and its feature may not be available on your device at all.

Hide/Show battery indicator in Task bar

If you wish to hide the battery indicator in the task bar on some devices, you can set:

HKLM\Services\Power\ShowIcon = 0 (DWORD decimal)

And to show:

HKLM\Services\Power\ShowIcon = 1 (DWORD decimal)

Note that this icon and its feature may not be available on your device at all. For example, the HTC Wizard regularly ships with a battery indicator in the Tray instead, governed by "Windows\Startup\Init_Tray.exe"._
_Note also that this reportedly does not work on AKU2 ROMs to remove the new battery indicator

Show slide-out keyboard caps/dot icon next to SIP

If your device contains a file called "capnotify.exe", try running it (most devices that have it will already have it in the Windows\StartUp\ folder), and setting the following value to get a visual presentation of whether you are in caps or dot (alternate key function) mode:
HKCU\ControlPanel\Keybd\EnableIndicator = 1
Please note that if your device has no external keyboard with caps/dot mode, you won't gain anything from this tweak
Please also note that the application "CapNotify.exe" must be running (normally found in \Windows\StartUp\ already) for this to work

Put custom text on bottom-right of Today screen

You can set some piece of text on the bottom-right of the Today Screen by setting the following key:

HKLM\Software\Microsoft\Shell\DeviceBeta\Today = "Hello World" (REG_SZ string, no quotes)

Please note that this text won't take up Today item text. It will be obscured by Today items.