On Twitter, can I send a direct message to someone I am following, but they aren't following me?

[Kato]

To answer the question about direct messages: you cannot send somebody a direct message if they are not following you. But you can however send a public reply to them (using the @ symbol before their name) and ask them to follow you.

To answer about writing on someone's wall for Twitter: there is not "wall" on Twitter like Facebook. But you can send them a public reply, like I stated above, by adding "@" in front of their name. When they go to the "replies" tab they will see your message. This is the closest thing to somebody's "wall" on Twitter.

Tweet me if you need more help: @katocollier
http://www.twitter.com/katocollier