Smaberg at XDA Developers has released a 12-button action screen for Xperia for quick access to some of the basic tasks.

Installed to the main/phone memory, the action screen is automatically assigned to the Power Button. Invoked when the power-button is pressed for 3 seconds, it displays 12 quick-launch buttons:

• E-Mail – Compose a new email message.
• SMS – Compose a new SMS message.
• MMS – Compose a new MMS.
• Appointment – Add an appointment to your calendar.
• Task – Add a new task.
• Note – Add a new note.
• Contact – Add a new contact.
• Wifi – Toggle Wifi.
• Bluetooth – Toggle Bluetooth.
• Camera – Start camera.
• Softreset – Restart the device.
• Power Off – Turn off the device.

A very handy utility but the biggest drawback – doesn’t work in WVGA, does work but in 480x800 resolution rather than 800x480 (thus part of the action screen goes out of screen bounds. If you want to test it out, go here.