Firstly, I don't think you wanna strap a camera with that lens around your nexk. If you were to do so, it would be better to whole the lens, with the strap securing around your neck. If not, you can always strap it round your shoulder right? I think that will make it easier and less straining on yourself as well. =D
the 70-200 is nothing compared to the bigger lenses!
even if i had the 300 2.8 i would still put the strap over my neck
although i hardly use it that much now, i just wrap it around my hand, and hold on tight.
You get used to it eventually - it's advantageous to be rather big built if you want to carry a lot of loads around, because ultimately, if you are bigger, you can carry more without causing too much problems to your body.
A 70-200 shouldn't be too much of a problem to sling around whole day (if you add a body and vg, it should be 3kg), though slinging on the neck isn't too comfortable, so I sling mine around my shoulder.
Usually in my bag. Then when i reached the site, i unload the equipment, load the lens and strap it either to my neck or handheld all the way. Unless there is a need for a smaller "pistol" i will have the 70 - 200 on all the way.:bsmilie: