Really Understanding Linux CPU Load (blog.scoutapp.com)

I wish I could upvote this more than once. Thanks for the submit! Crazy useful/interesting article!

I think that all articles should have a mandatory cars-on-a-bridge analogy.

This really isn't a very good analogy. CPU load isn't a necessarily a measure of CPU contention - it's simply the average number of processes running or waiting for disk I/O at any time. The latter is increasingly often the issue at hand, and tends to affect load much more drastically than CPU-intensive tasks.