"Thumbs-up" symbol

I'm looking for two icons to indicate that something is either OK
(up-to-date, correct, checked, etc.), or not OK (out-of-date, incorrect,
unchecked, etc.). I thought of using a "thumbs-up" and "thumbs-down"
icon, but I'm not sure how widely it is understood.

The "thumbs-up" looks like a fist seen from the side with the thumb
pointing up, the "thumbs-down" is the same upside down. Something like 
this:

           _
          | \
          |  |
          /  |
         /  /___
    ____/    ___>
             ____>
             ___>
    -----_______>



I know this sign is recognized in many countries, but I don't know how 
many, or if there are any where it has a different meaning.

I know the "thumbs-up" could also mean hitchhiking, but the
context will probably take care of that.


Bert
-- 
  Bert Bos                                ( W 3 C ) http://www.w3.org/
  http://www.w3.org/people/bos/                              W3C/INRIA
  bert@w3.org                             2004 Rt des Lucioles / BP 93
  +33 (0)4 92 38 76 92            06902 Sophia Antipolis Cedex, France