These lights from Luna Light Technology make it possible to see your dog from a goodly distance. The collar is choke free and has both luminescent and reflective technology to make it easier to be spotted. Both the collar and the lead have the same type lighting on them, making it simpler for people to spot dog and handler. Collar and lead are weather resistant.
[From http://www.lunabrite.com/lunabrite.php via Coolest Gadgets]