I really could care less about the folks with 800x600 display settings,and I think they are distinctly in the minority these days; sure, when a 15 inch momnitor was common, a display setting of 800x600 was common, but even my eight year old 12 inch iBook has a higher display setting than 800x600. People who are interested in photography and imaging typically have big monitors, well above 800x600.
Not many people are hosting their photos here on TPF servers, so the burden,what little there is, is not on TPF's servers, but on the actual hosts of the photos being linked to--pBase,Flickr,SmugMug,PhotoCamel,PhotoBucket,etc,etc. Honestly, a photo that is 800 pixels wide on the long dimension is pretty skimpy in terms of showing image quality, lens quality, or a photographer's technique. Images shown at 800x long dimension might as well be shot on a 2MP point and shoot as with a 21MP 5D-II. people posting images that are 300 to 400 pixels on the long side and asking for critique is what the OP was about; I saw three landscapes shown that today, at about that size, and there really was nothing to "say" about the photos. I saw an early 7D beta tester who shot some pics around NYC, and at the typical small Flickr size, a horribly,horribly out of focus shot of a pretty girl in front of a wrought-iron fence looked in-focus and fine on the web--but at 1600 pixels, it was clear the guy had blown the focus by at least three to five feet behind her.