I think that is a great idea. It doesn't take too much effort to go over and mow the lawn next door or send your teenager over there to pick up trash or leaves. It doesn't need to be the greatest job ever. Just enough to keep the home from being an eyesore.
Neighborhoods with homeowner's associations sometimes use the general funds to have this taken care of and to keep the neighborhood looking nice. But even places without an association would be well served to kick in some money towards this or just do it out of the kindness of their heart.
It's not their duty by any means, however, this helps them out as well. It helps a little to keep their property values from tanking, and it probably enhances the chances of getting good neighbors in there.
My point is that it doesn't take a lot to do this, and the benefits are probably well worth it.