Basically what it boils down to is just trust your instincts and keep your wits about you. Sticking to solid, populated and well lit routes (or cycling in numbers) should definitely minimize your ability to be victimized. Ride/walk with confidence, not with your head down. Making yourself appear as a victim/easily victimized also increases chance of attack. My experience, even though it did NOT result from a random attack just tends to make me extra-paranoid. 'Tis an experience nobody should ever have to go through.

As far as defending yourself goes, yeah I said eye gouge. That's only if you have the opening though. You have to feel each situation out as it goes, since I also said plans tend to fall apart once the situation has actually happened. Being on a bike most likely has its advantages in an attack situation. If they are in a car, you can squeeze into places they cannot. If they are on foot, you are faster, and bikes can HURT if necessary but I wouldn't recommend that unless it's a last-ditch effort to save your skin. Well.. I at least used to be able to tail-whip/wheel-whip people, but my balance for that has since disappeared with time, heh.