It seems for this type of "twitition" you need to have a twitter account.
The good thing about Twitter (unlike facebook and other social media sites) is that it allows you to have an account without exposing your identity to the world.
It only asks for a username (which can be any name you like) an email address (uncheck the box below this setting which reads "let others find me by my email address" if you dont want others to find you) and lastly, toward the bottom of the settings page you can click on tweet privacy which makes anything you "tweet" private. In other words, you can have a twitter account without anyone accessing you, emailing you, finding you or following you.
However, I know that there are those of you who are uncomfortable with putting info, no matter how little, on the net and that is okay. If you have friends who are already "tweeting", pass it on to them and help grow the list.
The most important thing is to get people's attention and get a database going so sharing is every bit as good as signing.