Build an everybody-can-use Application

Answer the questions below and you can create an everybody can use App:

[1] List 3 websites you use on a daily basis.
(me: google calendar, php.net, youtube.com)

[2] How did you first hear about them (if you can still remember)
(me: friends recommend)

[3] I assume that you heard this before - if you know 20 people, then you know everybody on the planet. So, how would you get people to invite their friends to your site?
(me: I would recommend a site that saves my time)

[4] Last question is, how could you help a blind person to use your site? (Just a concept...)
(me: do every little bits to help the users)