Inventions I'd like to see

• Instead of a wristwatch, why can't someone invent a time-telling tattoo? A temporary one would be better than a permanent one. It would be digital dots on the skin (you know: the 88:88 pattern) and powered either by movement or by solar energy.
  
• Big, refillable water bottles are cumbersome to carry, and those who are committed to not using the plastic throwaway ones are kind of stuck when they're at an airport. How about a collapsible water bottle that wouldn't get the TSA in an uproar, especially now that USAirways is charging $2 for water on a flight?
• The library labels that gradually change color: I still want to see those come to pass.
  
• Ditto for digital, easily downloadable versions of books (scholarly books, not Tom Clancy or Candace Bushnell).

I was going to add bottled versions of the smell of morning air to this, but there really isn't any substitute for that, is there? The cool air that smells so good that you can almost taste it at about 6 or 7 in the morning: if they could add that to airplanes, air rage would be a thing of the past.