For the most part, cage drivers are the biggest obstacle to making it home in one piece. The general consensus is that bikes are hard to see. IMO, anything is hard to see if you're blind, retarded and on a cell phone eating a hamburger, so as far as I'm concerned, it's not that we're hard to see, it's that blind people (drivers) don't see much of anything anyway.
It's no reason not to ride, though. All you have to realize is that a cage tard will NEVER do what they're supposed to, and they will ALWAYS do whatever will jam you up the most.
A few around here have signatures to that effect.. and it's definately true.
Once you learn to expect them to pull out in front of you, and swerve drunken into your lane, you get the hang of this cage-avoidance stuff real quick.
The most important things, IMO, are:
Never hang out in a cage tards' blind spot. They can't see you when you're right in front of them, so they REALLY can't see you in their blind spot.
Always be either in front of or behind a cage or cages. (Most applicable on a freeway) Never ride along side a cage for any longer than is required for you to either pass them or fall behind them. You can handle them braking in front of you a lot better than them coming at you from the side.
Just expect them to try to kill you, and you'll do well at avoiding them.