Upload & Sell: Off
One thing I noticed though, on a display with big pixel pitch, such as a 55" 1080p plasma HDTV as an extreme example, the noise WILL be noticeable. Or maybe it's because the TV has less colour gamut? Perhaps that explains why some people seem more critical than others about noise.
This image looks like a slightly grainy B&W pic on my calibrated 27" 2540x1440 IPS monitor but when I streamed it to my 1080p TV, I could REALLY see the noise.
I think that you have struck at a significant issue with regard to viewing web images, and that issue applies not only to noise but also to other aspects of image quality.
The issue is that you have people viewing images on a wide range of screen types. You still have some using older low resolution monitors. Some might be using what is essentially a 1080i laptop screen. Others might be using a 1920x1080 24 or 27 or 30 inch monitor. Still others are using higher resolution screens or larger screens. The result is that, while an image prepared for the web might look great on one screen, it can look awful on another.
I know that I do not have nearly the skill at preparing images for the web as do most who have posted in this thread, but having images look great for the web has never been a priority for me. Over the years, I've discovered too many times when people have used my images illegally and without permission. I finally decided that, for me, the solution I liked best was to use relatively small images (usually only 700 pixels on the long end) that have a fairly high level of jpeg compression. Having done so, I know that I can't stop others from using my images, but there isn't much that they are going to be doing with a 700 pixel long and highly compressed image. I do understand that, by doing things the way that I choose to do it, the images are not going to look nearly as impressive as they might otherwise look, but my purpose for images on the web is only to give people a general idea of what the image looks like, and my highest priority is how the images look in print, and, as several others have said, in print, much/most of the noise that looks awful at larger magnifications on the screen disappears.
That said, I'm really enjoying looking at the work of those who have posted in this thread. Generally, I don't shoot my 7D at ISO higher than about 1600. The reason for not going higher is that, for the shooting I do, the images lose visual appeal to me for reasons other than noise when the light is such that I would need to go higher than 1600. And, at up to 1600, I find that the noise is not an issue without having to use extraordinary means to deal with it. But, after seeing the techniques that some have used at even higher ISOs in this thread, I think that I may give some higher ISO shots a go and try using some of the workflow suggestions from those have posted in this thread. Many thanks to those have shared them.