I think this may have been discussed elsewhere but I'd like to drag it up again. If you have a photo or image on a page, how do you go about describing it? I'm thinking here also from the perspective of the Lynx user - is it best to do something like this for example alt="image: man sitting at computer" or just alt="man sitting at computer". What about characters like colons in alt or pipes, good idea to use them or not?
rough and ready rules of thumb that i usually try to live by:
describe the purpouse of the image, and not necessarily the image itself. (e.g. "back to top of document" rather than "bevelled blue arrow pointing upwards").
purely decorative images (e.g. a patterned border, swirly separator image, etc), put an empty alt="" in.
in cases in which the image is decorative, but tries to convey some kind of "emotional" or whatever value, you could do for a dual approach of having something like "a dynamic company with friendly service (image: smiling female telesales operator with headset sitting at workstation)" or something similar.