All it takes is to pick up after yourself and to pick up one or two other pieces of trash and you will be able to see a big improvement in our environment. People that are lazy, and I used to be one should not leave a mess everywhere they go, plain and simple.
There are plenty of trash receptacles all over the place, USE THEM!!! As for dog owners that don't pick up after their dogs, they are boneheads as well, it takes one second to reach down and scoop it up. If I don't have a bag with me, I go back to get it.