I have a D80 with a fairly large lens which weighs the camera down and whenever i am hiking/walking long distances it gets annoying because it isn't parallel to my body. Are there any solutions? Like special holsters/belts to keep the camera parallel to my body? Or at least more secure in some fashion? I don't like it bouncing on my chest gives me a rash and the camera gets worn out form constant friction.
Check out the Cotton Carrier vest, which holds the camera vertically tight against your chest. I haven't used it myself, but do know others who are happy with it.
This is an easy one! Once I figured this out I've never carried an SLR around my neck since. Simply put, wear the strap around your shoulder, but put your arm through the other way, so that with the lens hanging down the pentaprism is against your body. I tend to tuck the lens behind my waist, and hold the camera against my body with my arm/elbow, which keeps it from bouncing around all over the place. If you're right-handed like I am, then there's an added benefit: the camera's grip is in a perfect position to grasp with your right hand and bring it to your eye with one swift motion, and the strap remains behind your shoulder; if it's the right length you can maintain static tension and use it to steady your camera, much like a rifle shooter would with a sling. Once you get the hang of this, it's as fast if not faster than having the camera around your neck. Plus you don't look like a tourist, and your camera's less conspicuous. If you're wearing a jacket, the camera remains hidden; great for security and street shooting. Practice this a bit before trying other solutions, and even if you do go with different straps or harnesses, you'll likely work off a variation of this. Hope this helps!
I like straps that plug into the tripod mount, so I tried the Black Rapid strap and it worked okay. The whole strap felt a little cheap, but the sliding connecter worked well, although it did have a tendency to bounce around a bit unless I deliberately locked it back into place.
I tried the Cinch which worked very well. No sliding connection (two mount points) meant it's a bit harder to pull up and use because because you have to tug the strap, but it stabilizes the camera much more when walking. The only downside was if you added a vertical grip, it became difficult to hold the camera vertically because you had this nub sticking out of the camera. Then they released this flat rubbery connector which works perfectly.
I gather that the question assumes "not in a case or bag", but for the benefit of others who may not have that restriction: Tamrac, Case Logic, Lowepro, and other bag-makers have some easy/fast-access bag designs that allow the camera (and lenses, etc.) to be carried more or less like a backback, but easily slung around to quickly access the camera.
Beside my other answer, I've found another way to use the shoulder strap to hold the camera with its lens in a fairly nice way that prevents the camera from moving in an annoyingly.
Try to spin the shoulder strap couple of times till you make a node as shown in the next photo, then put it on your shoulder. Make the lens face the ground, the weight of the camera and lens weight will hold the camera steady.
You can also move it to your back