The warning is by LED and optionally a sound, and won't interfere with other programs or power off.

At power-off, there is a longer, clever warning once you cover the lens, it dismisses itself.

In contrast to other programs, LensWarning achieves its purpose by direct polling of the lens, so it is very safe, fast & reliable - the code is very small and optimized for the task - it won't crash your other ARM applications, and it won't slow you down.

In addition, LensWarning has some nice extras when running any of the camera applications:

• You may start them with full brightness (100%),
• You may extend the auto-off timer (restored on exit),
• You may toggle between STILL/MOVIE shooting apps, using the VOICE REC button (only when inside one of the camera applications already).

LensWarning for Sony CLIE(R) handhelds with camera. Tested under TH55 only - may work for others too.

Update: Reported success on TJ27 too.