My company just deployed a dozen Windows XP touch screens in conference rooms to control video conferencing systems. We're using all-in-one PCs with no keyboard or mouse attached, so the only way to wake from screensaver is to touch the screen, which is of course interpreted as a click.
The problem we're having is that the click is passed through to the top app -- our video conf control system -- causing the user to take some action (like hangup) that they didn't intend.
We do need to have a screensaver, the PCs are turned on 24x7, and the control app is visually very static. We expect a simple bouncing image screensaver to significantly lengthen the productive life of the system.
Is this something we can tweak? The screensaver content is a single bouncing image, so I'd be open to replacing the screensaver, or tweaking the registry, or (best) pushing the change via Active Directory (all the affected systems are already grouped into a specific OU).
It sounds ridiculously obvious but... disable the screensaver for those machines via Group Policy?
EDIT:
Why not change to a screensaver that still displays the desktop, but obscures it to help prevent burn in. This would allow the user to see a clean place to "press", and would still protect the display. A perfect example would be the Bubbles screensaver. There are many more like this.
(source: wareseeker.com)
If the touch screen is LCD based then a screensaver is not actually necessary to prevent burn in. You may still be required to use one for security reasons but should not just to increase the life of your LCD.
OK since we seem to have established that not using a screensaver at all may actually be a bad idea, here's a few left field ideas.
Since this seems like a reasonable problem that needs to be solved ask the vendor to update their app so that it integrates a screensaver behavior that consumes the wake up tap action.
This might sound a bit silly but if you set the screensaver delay to a time that is longer than the average duration of the meetings that use the rooms then the risk of users accidentally tripping an unwanted action should drop substantially.
Tape an overlay to the side of the screen with "Wake up" or "ON" with an arrow pointing to a spot on the screen where no action will be taken. Or a label that looks like the iPhone unlock screen with "Slide to unlock". Obviously not being able to overlay it on top of the touchscreen might present some usability problems.
If you have any half way smart programmers in the company they should be able to throw together a screensaver that will consume the wake up tap for you.
Just a thought... What happens if you wipe the finger along the screen instead of just touching it? It seems to me that should be equivalent to moving the mouse, rather than clicking it. If so, perhaps a little sign or user education might be all that's needed. Hardly an ideal solution but perhaps a workable one?
You could change the screen saver to add a password after it wakes up, that way the click would send you to the password screen rather than the app.
Also this would add security the the situation of always having the computers on.