Save this link on your cell phone if you have Internet (thanks again al gore) and you can enter in the info so the offender will get a warning letter. Just don't do it while driving, get the tag and do it when safe.
Swat a litterbug
or enter this
http://www.ncdot.org/doh/Operations/dp_chief_eng/roadside/Beautification/Litterbug/salform.html
go here