Another "best practice" would be if the OP could put "pictures" "pix" "high res" or something in subject line. Then Greg et al dial-ups could avoid clicking if need be.
But then again sometimes a topic may need a picture in mid posting and that would not be reflected in subject.
I guess if not a "picture" topic area or disclaimed in subject, trying to keep screen caps, and other pix in the low couple of hundred KB's is a good compromise. (my dad has even learned how to "save as" and resize so he now emails 300-400 KB pictures instead of the raw 3meg 2600*2100 images)
Andrew