If that's true, that should be illegal. Besides, photobucket, imageshack, and (I'm not sure about this...) flikr, all allow it. And, I haven't seen any other hosts here.
It wouldn't be that hard to teach.
On imagechack it's in big bold letters, and I don't know about other hosts. You can also right click on it, and copy image location. In IE, you can right click > properties. The link is there.
Depending on speeds of internet, it does.