Those thoughts came to mind. :-D Also interesting that you could use it for signage on 'unusual' surfaces- glass storefronts, say (on second thought, optical trackers don't work well on glass; you could trick it by sticking up a bit of screen if they never make a specialized variant) ... load it with an etchant and do a piece of stone, or a mask material for doing circuit boards...
As downsides, I'm sure folk'll find it hard to *avoid* marring furniture with these, as it naturally rests jet-side down (darker surfaces could be saved by reflectivity-detection), and I'd hate to see some poor mail clerk stuck 'ironing' a stack of envelopes for hours on end - hard to imagine a quicker path to RSI.