Inaccessible downloads
The Internet, in theory, enables anyone from anywhere to access information. In reality all the people with dial-up connections are cut out of a lot of it. I know that in the States and Europe almost everybody has some kind of high speed connection but the rest of the world is still using dial-ups. I'm not a professional of the web but I like it because it has brought more freedom to people, more opportunities to learn.
Podcasts, videocasts,screencasts: there should always be a text version that can be downloaded by everyone.