Visit www.countycomm.com and buy a few dozen of their $1.00 keychain LED lights. Give one to each co-worker and tell them to EDC it on their keys. These Photon II clones are also ok, a bit harder to operate but they don't get turned on by accident as easily:

http://www.qualitychinagoods.com/ultra-bright-plastic-keychain-light-white-p-280.html

The Countycomms are probably better for PSK's because they don't turn on with squeeze pressure, and a piece of scotch tape over the slide switch keeps them shut off until you remove the tape.