Twittering is trial and error. Another way to twitter, I think, to someone's page is to use the @ sign before the username. It will go to that person's site as well as your own site. Again, I am only guessing and as more folks use Twitter, us dinosaurs might actually learn how to use it.
1. to direct a message to a specific person use direct message either on the computer or if on phone text d space username space message to 40404
2. the @ in front of a name also will let that twit appear on the username's page but also it will be seen by all who are following that person as well, I THINK
3. Twitter is not an exact science, if you learn something, post to me and i can post to the blog