A laser cut business card that folds into a working caliper.
The cdr file will probably work best, it\'s setup for an epilog laser cutter.
Once you cut it out, snap out the slider and the rule. Fold the rule on the scored dotted line, wrap around the caliper body, and instert the tabs into the slots.
Depending on what paper is used, the design may need to be tweaked a bit to make everything line up correctly. The uploaded design seems to work well on light card stock. If you can find paper that has a printed layer and a white background, the engraved portions show up better. The paper used in the pic was from a notebook folder.
Some more pics at http://www.flickr.com/photos/alikins/sets/72157621345169498/ Some pics and comments from development at my blog, http://adrianlikins.com/2009/07/business-card-caliper/