The best way I have found around the fear and disease factor is to find people to video cam with. You don't show your face, just the important parts. Yahoo Video Call is better picture quality than just regular cam, and you can both hear the other. You can talk about your fantacies, each others cock, past experiences, what you would like to do, or even roll play that the two of you are actually doing it until you both cum.
It may take a few tries to find the right person, or persons. If you can find several, that is better, because you can't always hook up with the other person when you want to. It's not exactly like being there, but it is safe, and is very sexual. If you're open and verbal, you won't have any trouble getting off. Just don't get off and shut down the cam and leave the other person hanging.