First off, I'm glad that there's a reasonable tone in this thread, it's reassuring to me that our forum community manages, even in the context of what started as a rant, can have an intelligent discussion without sniping and attacking.
There are fools/tools on the road -- riding bicycles, riding motos, driving cars, hell, even walking. By their actions, they certainly don't earn our respect. And I know I'm as guilty as any when it comes to letting some bozo know how I don't approve...
But what concerns me about a thread like this, is that they feed into the running, internal dialogues we all keep within ourselves. Yeah, we all see folks acting stupid, and yeah, we don't like it. Got it. But when we rant and lump others, we allow a potentially hurtful mindset to persist and fester. And the next thing you know, someone's using their car to plow into a pack of cyclists.
There was an incident here in the East Bay area back in the early nineties where a woman went nuts and plowed into a group ride. To this day, I see one of the guys who was hit that day -- he's lucky as he survived, I think two or three others weren't so fortunate. He's got a prosthetic foot and still rides.
I guess I'm trying to suggest a "live and let live" and "do unto others" notions really do go a long way.
If you see cyclists -- solo or a group -- up the road, give a toot on the horn from a distance. I'm with Pete, if I get honked at by a vehicle when they're right next to me, I'm not too happy about that. If I hear a toot from a distant, approaching car, I move and wave in thanks.
From my experience, when riding a bicycle, it's tough to hear cars coming from behind. Even if I'm not riding with headphones on. Those little cycling helmets don't cover the ears. There's a lot of wind noise. And modern cars are pretty quiet. Getting surprised really sucks.
Perspective, patience, and compassion go a long way.
[stepping off of soap box]