My thermostat has this feature- a "clean me now" button that suspends all buttons until the countdown (30 seconds) is completed. During that time you can wipe the screen clean.
I find that my WebDT gets fairly dusty- with a suspend button I could avoid powering down (or suspending the device) to clean it. At the end of the day with the quick the WebDT resumes very quickly from a suspend, but I think I would prefer not having to do this.
Don't have the slightest idea what this would take...
Hmmm...thats actually a very nice idea :-)
Will have a look at that and report back here.